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M852

DIY Bluetooth Interface for ProChrono Digital

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So, after following the original DIY Serial Cable thread a couple years ago, I finally got off my duff and went the Bluetooth route. I procured the BlueSMiRF Silver Bluetooth Modem (to TTL Serial) and a CP2102 USB to TTL Serial breakout board from Sparkfun. The BlueSMiRF Silver is based on the RN-42 bluetooth modem and is spec'd to about 18 meters. The BlueSMiRF Gold is based on the RN-41 bluetooth modem and is spec'd to 100 meters, but I don't know if it will handle the 1200bps needed to communicate with the ProChrono.

BlueSMiRF Silver: https://www.sparkfun.com/products/12577

CP2102 USB to Serial Breakout Board: https://www.sparkfun.com/products/198

Using a WinXP box, I was able to setup the bluetooth modem using Hyperterminal by connecting the modem to the CP2102 breakout board (installed the drivers for the CP2102 first). Sparkfun's BlueSMiRF page says it's baud range is 2400-115200bps but the Roving Networks documentation specifies 1200-115200bps. I was able to configure it for 1200bps without any trouble and I left it's default of slave mode.

The beauty of the BlueSMiRF modem is that it will accept 5V at the VCC pin as it has an internal voltage regulator and level shifter to drop that to 3.3V. I used a four cell AA holder and stuffed it with NiMH rechargables (for a total of 4.8V) which is within the acceptable range for the BlueSMiRF's onboard regulator.

Now, getting it connected to the ProChrono Digital:

First, I soldered a male SIP header (1x6, but a 1x4 would work as you don't need the RTS and CTS pins) to the BlueSMiRF. Next, I cut off one end of a stereo 3.5mm audio cable (to about 3ft long), removed about 1.5 to 2 inches of the outer audio cable jacket and stripped and tinned 1/4 inch of exposed wires (used heatshrink tubing to cover the bare ground wire up to the last 1/4 inch and twisted it around the negative wire of the battery holder before soldering them together). Using a DVM, I rang out the Tx (tip), Rx (ring) and ground (sleeve) wires and soldered them to a female SIP header. It is important to solder the audio cables Tx wire to the female SIP header pin that will connect to the Rx pin of the BlueSMiRF's male SIP header and the audio cables Rx wire to the correct pin to interface with the BlueSMiRF's Tx pin. Moving right along, I soldered the battery holders positive (red) wire to pin of the female SIP header that interfaces with the BlueSMiRF's VCC pin and the battery holders negative (black) wire which is soldered together with the audio cables ground wire to the GND pin on the female SIP header. Then I soldered a 10k resistor between the BlueSMiRF's Rx and GND pins on the opposite side of the board from the header (for the not-so-technically-inclined, this is the same as putting it across the Tx and ground of the ProChrono as mention at least a couple dozen time throughout these threads).

* Just a side note: I noticed the CED FT232RL based USB to Serial adapter uses a 4.7k resistor instead, but I haven't tried that to see if it will work here.

Here is where I plug the female SIP header (that's soldered to the 3.5mm audio cable and battery holder) into the male SIP header on the BlueSMiRF making sure that the orientation is correct so the battery positive is engage with the VCC pin of the BlueSMiRF. Finally, I connected the 3.5mm audio plug into the ProChrono and loaded the battery holder with freshly charged NiMH AA batteries. Turned on the ProChrono, paired my Android to the BlueSMiRF modem and launched a bluetooth serial terminal emulator I downloaded from the Google Play store. Sent the change string command (:000000057B) and, VOILA, the ProChrono changed strings. Tried it again, and again, success. Next, I shot a few nerf darts over the ProChrono, the terminal received some data (strings of data I couldn't interpret without studying the communication protocol uploaded earlier in this thread). So, I would consider that a HUGE success.

I could not, however, unzip the app uploaded to this thread by BenOZ. So, as soon as somebody can upload an app here or get one to the Google Play store, those of us who have successfully bluetoothed our ProChronos will be able to play, test and get feedback to our generous ;) app coders out there. Also, for the record, I was able to connect and control my ProChrono from my Windows Vista laptop using my BlueSMiRF rig.

I will try to upload pictures of my build soon.

** Important side note here: The BlueSMiRF modem uses a different AT command set than the HC-05/HC-06 bluetooth devices previously mentioned in these threads. So, USE ONLY THE AT COMMAND SET IN THE ROVING NETWORKS DATASHEET WHEN CONFIGURING THE BLUESMiRF MODEM!!!

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So, after following the original DIY Serial Cable thread a couple years ago, I finally got off my duff and went the Bluetooth route.

Excellent! Can you post some pics?

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I could not, however, unzip the app uploaded to this thread by BenOZ. So, as soon as somebody can upload an app here or get one to the Google Play store, those of us who have successfully bluetoothed our ProChronos will be able to play, test and get feedback to our generous ;) app coders out there.

Try the attached file.

Main2.zip

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Cool. Thanks M852. I took some pictures and had a short time to play with the app. I won't be able to upload the pics until later this evening or tomorrow. Life keeps getting in the way of fun, but I think we're all familiar with how that goes around here.

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Well, after trying multiple times in multiple browsers using different methods for the last four or five hours, I was unable to upload pics of my BlueSMiRF to ProChrono project. It kept telling me "An error occurred: You are not allowed to use that image extension on this community". They are in .jpg format and I made sure all images were 600 pixels or less in width. Maybe I tried to upload too many at once? Or, maybe I need to re-re-review the forum FAQ's/guidelines? However, I'm pretty sure these should have been okay. UGHHH, if anybody knows what I'm doing wrong, PM me instead of replying on this thread so we don't blow it up with junk.

...It wouldn't let me post this with a single image here either. :angry2:

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Glad you got your unit up and running, elchupacabra. I just got mine finished a couple of days ago. Heres some pix.

Front view:

post-53549-0-45289500-1415033593_thumb.j

Side View:

post-53549-0-63579000-1415033644_thumb.j

Bottom View. The plug is epoxied in so it just plugs in the side of the chrono and the velcro holds it in place.

post-53549-0-31166700-1415033779_thumb.j

Inside view. The packing foam that holds the battery in place is removed for visibility.

post-53549-0-08856100-1415033877_thumb.j


It works just fine with CE's software, but I keep getting timeouts with the android app. Not surprising since I know squat about smart phones.


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So at first i want to introduce myself, I am from Germany and I am a 21 year old electronic-student. So please don't be too hard to me, because English is not my main language and i haven't used my English for a long time, but i think you will understand me :)

I'm very thankful for this thread, because it was the primary idea for my project and without this thread, I wouldn't have done it!

I bought the Chrony half a year ago and it didn't worked indoor because of the light. So I decided to build my own lighting, but it didn't worked and looked very well. That was the reason to buy the original lighting system (about 65€). After 2 weeks the lighting system arrived and I had to observe that the transformer is working with 110V not with 230V. I know there are adapters but I didn't want to use one.

So my idea was to provide the Chrony and the lighting system with a Lipo-Battery (18.5V, 5000mah).

After searching via google I found this site, and saw that there is a way to use a bluetooth connection...okay a lot of input... . After three days of thinking I knew what i have to do:

Here are my requirements:

- Using a battery (runtime over 10h)

- Undervoltage Shutoff (if you forget to turn the Chrony off)

- Voltage Indicator via Duo-Led (Green, Orange, Red)

- Bluetooth with range >50m

- Chargeable without effort

- "Clean" optic (It should not look unprofessional)

So let's start with some pictures:

ld4oahsf.jpg

Here you can see two Bluetooth modules (BTM222 - maximum range 100m) and 4 Step-Down Converters (Pololu 9V and 5V). Don't wonder yourself, i am building two Chrony's :) (for me and a friend of mine)

So that is the inside of the Chrony, i have used hot glue to hold the connector in place. The connector is used to charge the Chrony. The eight pins of the connector are used for plus,minus and six of them are used for balancing the individual cells.

fuyg7mq3.jpg

452uowu5.jpg

Here you can see the loading cable:

yalgb5ob.jpg

And the charger from ebay for 30€.

viqgrx9n.jpg

I have used the following battery.

T5000-5-20.jpg

Turnigy 18.5V 5000mAh (35€)

I wanted to provide the lighting system with voltage over the rods. But at first let me show you some pictures.

Here ("plastic thing") are the short brass jacks in it. The wires are soldered with the brass jacks.

http://fs1.directupload.net/images/141228/oc6ply4k.jpg

long&short brass jacks and two "connectors"

http://fs1.directupload.net/images/141228/pisr2dnm.jpg

It fit's well :)

http://fs2.directupload.net/images/141228/dwa93tst.jpg

http://fs1.directupload.net/images/141228/ga93jeck.jpg

http://fs2.directupload.net/images/141228/3xp9lf4h.jpg

Aluminium rods

http://fs2.directupload.net/images/141228/ysqofwe4.jpg

http://fs2.directupload.net/images/141228/vnyqfbkv.jpg

Short test...

http://fs2.directupload.net/images/141228/s5w3ok5s.jpg

Okay so I hope you can understand me...I have used aluminium for the rods because the original ones were to hard to cut a 3mm thread in. With my lathe I made the brass jacks. The jacks have an outside diameter of 5mm and a 2.6mm drilling. The connector has an outside diameter of 2.5mm.

So you need 8 brass jacks for one Chrony. Four in the lighting system and four in the black "plastic thing". I also have build in a bridge rectifier in the lighting system, so it does not matter how you put them on the rods (polarity protection).

On the next picture you can see the battery in a non-flammable bag.

http://fs1.directupload.net/images/141228/c74sonyx.jpg

And yeah it does not only look tight - it's really tight :)

Here you can see the Duo-Led (Green, Orange, and Red)

http://fs2.directupload.net/images/141228/29sl83p2.jpg

Green

Orange after 6h Runtime

Red after 10h Runtime

http://fs2.directupload.net/images/141228/cwvc5w3e.jpg

http://fs1.directupload.net/images/141228/tga88oeh.jpg

The main circuit with undervoltage protection, 2 Step-Down Convertor 9V and 5V, one Step-Up Converter for the lighting system 25,4V, the circuit for the duo-led...

http://fs1.directupload.net/images/141228/calwtwe9.jpg

If there are any questions feel free to ask me. The Chrony works perfect :) Runtime is 13,5h. Bluetooth Connection also works perfect but the greatest distance was 40m over this distance the connection isn't fast enough and it doens't work well.

Greetings from Germany

Johannes

Edited by Zodiak1993

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If there are any questions feel free to ask me.

:surprise:

Dude, you just got the Chrony Hack of the Year Award!

I've been stumped just trying to figure out how to add a power LED (not even multi-color) to my original design.

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Thank you very much :) It really was a lot of work, and there were so many problems that had to be fixed. So on the pictures you can see my "version 1" (for my friend :D). I changend some things in "version 2" for example the undervoltage shutoff. Version 1 needs 1.5mA, Version 2 needs 0.007mA (if battery voltage is too low). So it would be no problem to forget to turn off the Chrony over a month.

Also version 1 has a delay of about 1 second if you turn it off. Version 2 is instant off. But of course version 1 is also working fine, there were just little improvements in version 2.

I will show you some more pictures tommorow.

And thank you M852 for this thread, it was my first experience with bluetooth TTL - I wouldn't have done it without you :bow:

Edited by Zodiak1993

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That is slick. Welcome to the forums and thanks for a great first post. I look forward to your future posting.

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So here are some more pictures, of my Chrony (version 2 ).

h8lg6z75.jpg

I used an old wlan-antenna of my d-link router to increase the effective range. Its no problem to connect with the Chrony over 100m but if I am using the original software from competition electronics it doesn't work over 30-40m. The reason why this happens is pretty simple. The software is sending several commands in one second and the Chrony returns the last recorded velocity in a string (you already have talked about it here). If the distance is too far the BT-connection is too slow and there is a kind of buffer overflow...

Unfortunately I am not good at coding, and can't change it. If there would be just one command per second from the software I think it would work over 100m. I already tried to send the commands via Hyperterminal and it was no problem (distance 100m).

So the next step is, to create a new software with metric units :) But therefore I have to get better in coding.

44p4fj54.jpg

nyk33e6z.jpg

pudgbhq2.jpg

With this picture I just want to show you that the battery is chargeable during operation. So there will be never the case, that I cant measure my guns :)

Thank you for your attention.

Johannes

Edited by Zodiak1993

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Thank you for your pictures. I haven't found your thread before - you already had the idea 3 1/2 years ago :) And I think it still works perfect - simple but effective!

Here are the last pictures of the inside of my Chrony (version 2 ^^)

2ks67pp8.jpg

766saiva.jpg

qehn4m2f.jpg

c4e3yie3.jpg

If you want to know anything just ask me :)

Johannes

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Wow thats really hard, the just stole your idea :/

And I'm pretty sure the software won't work with our DIY-BT-Solution. It's for IOS and IOS doesn't support SPP (Serial Port Profile) so I think they converted the TTL Signal coming from the audio-jacket...

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And I'm pretty sure the software won't work with our DIY-BT-Solution. It's for IOS and IOS doesn't support SPP (Serial Port Profile) so I think they converted the TTL Signal coming from the audio-jacket...

Interesting. Not sure about iOS, but the Android software shouldn't care what the TTL transport mechanism is (e.g., Bluetooth, USB, etc.) just like the PC software. I'm definitely not a programmer, but I believe that would have been the least complicated/most likely to succeed route. It would be most unfortunate if the Android or iOS apps didn't work with a DIY solution.

Wow thats really hard, the just stole your idea :/

Yeah, there is that. <_<

They should send me a unit for free to make up for it. :D

Edited by M852

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They were shamed into doing it!. It's probably a microcontroller based system to supply the temperature and altitude readings. That means that we cant use the new software with our generic hardware like before. It would expect some sort of an identifying string from the microcontroller before it would work.

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I think that the smartphone (internet) supply the information about temperature and altitude. We will see if it works with our DIY Version ...

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Brand new here, but signed up because I ran across this post when trying to research and decide on a chrono for me to use with my android or ipad at the range and then export to the pc at home. So far, the Caldwell unit is released (wired only though), and it looks like ProChrono is close with a BT unit but not out yet.

And of course, I like to tinker (hardware), so the idea of building my own BT module appeals to me - especially mounting it inside and out of sight. The question is, how would I get the software side covered. The propsect of not having an app to use with it (my laptop is a behemoth-no way it's going to the range with me) leaves me pretty much at square one. Then I saw tonight that the CE app is available already on itunes (for the ipad at least) but won't actually show you anything unless it is connected to the BT unit. At least the Caldwell app (both android and ios) can be "played with" without being connected to get a feel for how it works, and doesn't seem too bad (mind you, I've never owned a chrono and am just getting into reloading).

So, I was wondering if anyone here that has built a BT module would be willing to see if it would actually connect to the CE software on ios or not. That would at least satisfy my curiosity on whether it is worth trying to build my own module (to use with their app) or just waiting it out to see how their app actually works and then deciding what to do.

I also half wonder if the Caldwell android software (which uses either serial over 3.5mm or USB-to-USB OTG adapter) could be made to read the output from the ProChrono (either via bluetooth or via the same USB-OTG adapter). Not knowing anything about code, I imagine they probably use different language or something and won't talk to each other.

It still blows me away that, given the compact size and power of microelectronics these days, that all of the chronos out there seem to be unchanged in both construction and programming since the 70s. How hard can it be to put something together that is compact, supports multiple output interfaces like BT and USB, and offers a software app for multiple platforms that can share across devices via a universal data format and export for users to plug into other uses as well?

And then there's the severe lack of any good data collection programs for reloading information and inventory...

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So at first i want to introduce myself, I am from Germany and I am a 21 year old electronic-student. So please don't be too hard to me, because English is not my main language and i haven't used my English for a long time, but i think you will understand me :)

I'm very thankful for this thread, because it was the primary idea for my project and without this thread, I wouldn't have done it!

I bought the Chrony half a year ago and it didn't worked indoor because of the light. So I decided to build my own lighting, but it didn't worked and looked very well. That was the reason to buy the original lighting system (about 65€). After 2 weeks the lighting system arrived and I had to observe that the transformer is working with 110V not with 230V. I know there are adapters but I didn't want to use one.

So my idea was to provide the Chrony and the lighting system with a Lipo-Battery (18.5V, 5000mah).

After searching via google I found this site, and saw that there is a way to use a bluetooth connection...okay a lot of input... . After three days of thinking I knew what i have to do:

Here are my requirements:

- Using a battery (runtime over 10h)

- Undervoltage Shutoff (if you forget to turn the Chrony off)

- Voltage Indicator via Duo-Led (Green, Orange, Red)

- Bluetooth with range >50m

- Chargeable without effort

- "Clean" optic (It should not look unprofessional)

So let's start with some pictures:

ld4oahsf.jpg

Here you can see two Bluetooth modules (BTM222 - maximum range 100m) and 4 Step-Down Converters (Pololu 9V and 5V). Don't wonder yourself, i am building two Chrony's :) (for me and a friend of mine)

So that is the inside of the Chrony, i have used hot glue to hold the connector in place. The connector is used to charge the Chrony. The eight pins of the connector are used for plus,minus and six of them are used for balancing the individual cells.

fuyg7mq3.jpg

452uowu5.jpg

Here you can see the loading cable:

yalgb5ob.jpg

And the charger from ebay for 30€.

viqgrx9n.jpg

I have used the following battery.

T5000-5-20.jpg

Turnigy 18.5V 5000mAh (35€)

I wanted to provide the lighting system with voltage over the rods. But at first let me show you some pictures.

Here ("plastic thing") are the short brass jacks in it. The wires are soldered with the brass jacks.

http://fs1.directupload.net/images/141228/oc6ply4k.jpg

long&short brass jacks and two "connectors"

http://fs1.directupload.net/images/141228/pisr2dnm.jpg

It fit's well :)

http://fs2.directupload.net/images/141228/dwa93tst.jpg

http://fs1.directupload.net/images/141228/ga93jeck.jpg

http://fs2.directupload.net/images/141228/3xp9lf4h.jpg

Aluminium rods

http://fs2.directupload.net/images/141228/ysqofwe4.jpg

http://fs2.directupload.net/images/141228/vnyqfbkv.jpg

Short test...

http://fs2.directupload.net/images/141228/s5w3ok5s.jpg

Okay so I hope you can understand me...I have used aluminium for the rods because the original ones were to hard to cut a 3mm thread in. With my lathe I made the brass jacks. The jacks have an outside diameter of 5mm and a 2.6mm drilling. The connector has an outside diameter of 2.5mm.

So you need 8 brass jacks for one Chrony. Four in the lighting system and four in the black "plastic thing". I also have build in a bridge rectifier in the lighting system, so it does not matter how you put them on the rods (polarity protection).

On the next picture you can see the battery in a non-flammable bag.

http://fs1.directupload.net/images/141228/c74sonyx.jpg

And yeah it does not only look tight - it's really tight :)

Here you can see the Duo-Led (Green, Orange, and Red)

http://fs2.directupload.net/images/141228/29sl83p2.jpg

Green

Orange after 6h Runtime

Red after 10h Runtime

http://fs2.directupload.net/images/141228/cwvc5w3e.jpg

http://fs1.directupload.net/images/141228/tga88oeh.jpg

The main circuit with undervoltage protection, 2 Step-Down Convertor 9V and 5V, one Step-Up Converter for the lighting system 25,4V, the circuit for the duo-led...

http://fs1.directupload.net/images/141228/calwtwe9.jpg

If there are any questions feel free to ask me. The Chrony works perfect :) Runtime is 13,5h. Bluetooth Connection also works perfect but the greatest distance was 40m over this distance the connection isn't fast enough and it doens't work well.

Greetings from Germany

Johannes

Holy shit that's overkill on that battery. That's too large for most of my RC planes that do 100mph!

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Couple of updates:

The good news: For those of you who didn't know, CED's Digital Link Android app for CED's Digital Link Bluetooth adapter (mentioned above) has been posted on the Google Play store!

The bad news: I have not been able to get CED's Digital Link Android app to work with the DIY Bluetooth interface. The Digital Link app gets stuck on "Looking for Digital Link...." and goes no further. However, BenOz's test app installed on the same Android device will still connect to the DIY interface. At this point, I suspect there is an initial handshake of some type between the Digital Link app and the Digital Link Bluetooth adapter. However, I'm a hardware guy, so I've reached the limits of my expertise in figuring this out. If someone knows how to sniff the serial connection between the app and the interface it may shine some light on how the Digital Link app is establishing the connection. Knowing that, we may be able to update the DIY Bluetooth interface to be compatible with it.

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It doesn't look like CED's app is available on the Australian app store for android or am I pushing the wrong buttons?

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It doesn't look like CED's app is available on the Australian app store for android or am I pushing the wrong buttons?

It's listed under the name Digital Link by Competition Electronics in the Sports category.

The link above to the Google Play store doesn't work for you?

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It didn't, now it does, having said that, I cant install it because it states 'This item cannot be installed in your device's country' A little strange! Does anyone have the APK file they could throw my way?

Edited by BenOz

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