DIY Bluetooth Interface for ProChrono Digital

[rwskinner]

Hey all, if you need help with any specific commands let me know. I had an interface going and hammered all the command out at the first of the year and wrote a small application to store load data into my database. I had all the interface right at 100% if I remember right but never did get around to the database portion due to excessive work loads.

Some of the protocol is poorly written and I think I would have gone about it all in a different fashion (code on the prochrono) but it is what it is.

Sending commands to get back the proper string data was a little crazy at first until I finally figured out you have to send certain commands in certain order then everything went very well.

Richard

[M852]

Hey all, if you need help with any specific commands let me know. I had an interface going and hammered all the command out at the first of the year and wrote a small application to store load data into my database. I had all the interface right at 100% if I remember right but never did get around to the database portion due to excessive work loads.

Some of the protocol is poorly written and I think I would have gone about it all in a different fashion (code on the prochrono) but it is what it is.

Sending commands to get back the proper string data was a little crazy at first until I finally figured out you have to send certain commands in certain order then everything went very well.

Richard

Although I'm a hardware guy, I can appreciate the value of the information you've collected and are offering. Many thanks for chiming in on the thread and helping us out!

If I recall correctly, the protocol was written about 14 years ago. Not being a coder, I wouldn't know jacked up code from pristine, but maybe the protocol was a product of limitations that existed in 1999?

[gmich]

Thanks for the heads up on this. I should finish this project. I tried a quad FTDI USB to serial for a PC interface and it sorta worked. I got a lot of errors. I then built a TTL buffer of my own design and interfaced to that and then to the quad FTDI module and it worked ok. I wonder if my (specific) chrono has problems with the serial output?.. it seems to have very little drive capability. With two high impedance 2N3904 buffers (one to invert it back to the correct polarity) it's stable.

I haven't actually used it yet (I'm still quite aftraid I'll shoot it) but I do plan on getting it out by the end of the summer. The only catch I see with the Bluetooth is the battery power... after I thought that through .. I'm not convinced it's any better than running 20' of cable. What would make it better is reverse engineering the protocol, but it's proven to be more difficuly than I expected. If I did, I'd write an Android app and THAT would make it worthwhile.

Someday.. probably in the fall and winter "when I have time again".

If you are worried about shooting your chronograph, there are steps you can take. After 15 years I finally caught the edge of mine and spent $50 getting it back in order. One time ignoring my safety precautions was all it took. Here is what works for me...if I do it. Bolt action guns, I remove the bolt with the gun on sandbags sighted into the target. Look thru the bore. If you don’t see your chronograph its all good.

OR… if you don’t have a bolt then buy a cartridge laser sight tool. Get one small enough to fit into most chambers, a 243 works good. Align it so your beam shoots down and out the barrel. Hold a white card in front of the chronograph, if you see the dot on the card you can easily determine if the dot would line up on the chronograph or over the chronograph. Really simple, so simple you will get lazy one of these years and blast the carp put of your Pro Chrono. No need to ever dust it if your careful and there is no need to ever own a chronograph if you never use it, Get out there and enjoy your chronograph. And in your free time make me a Bluetooth adapter, I built the cable but think the BT is over my head. After all, I did shoot my chronograph, how smart could I be? Good luck.

Edited December 12, 2013 by gmich

[w0fms]

Interesting and obvious.. I do have a universal laser and a cartridge one for .223.. So yeah.. That is obvious.. I do need to work on the project again.. I won a iPad mini.. And really, compared to Android I hate it... But I should look into writing an app for both. Thanks though.. I have a bunch of good functioning pistol loads that I need to chrono... -10°F tonight. .. It might be several weeks before I go out again.. . Thanks for the suggestion of the laser and bolt removable. I am mainly a pistol reloaded and shooter but yeah, both methods make sense..

[gmich]

Interesting and obvious.. I do have a universal laser and a cartridge one for .223.. So yeah.. That is obvious.. I do need to work on the project again.. I won a iPad mini.. And really, compared to Android I hate it... But I should look into writing an app for both. Thanks though.. I have a bunch of good functioning pistol loads that I need to chrono... -10°F tonight. .. It might be several weeks before I go out again.. . Thanks for the suggestion of the laser and bolt removable. I am mainly a pistol reloaded and shooter but yeah, both methods make sense..

I didn't mean to imply I discovered some unique method. As with most things returning to the basic is all we need. I just wanted to point out that you can get more use from a Chrono by using it rather than not using it because of fear of shooting the box. (another obvious statement) Simple but effective precautions can get you shooting and enjoying. Just don't skip the very basic ideas and you are good to go. As I learned, you can only forfeit these methods for so long before your number is up, or in the case of a Chrono not up. The 223 is small enough it should self center in almost any chamber and allow for a method to avoid hitting the box. Usually I just look down the bore or place a 2.5" block of wood on the front top edge of the box. Then I sight in for the to[p of that block. Since most scopes are 1.5" above the bore, you can be assured that if you are sighting in on something 2.5 to 3" high you will miss the box by at least and inch. Of course the block falls down from the blast as the bullet screams by but that is hardly an issue. Enjoy yourself, that’s what it’s all about either way.

Edited December 12, 2013 by gmich

[pobro]

seems to me this might be a good solution:

http://bulletin.accurateshooter.com/2013/11/new-caldwell-chronograph-displays-shot-data-on-iphone-or-ipad/

Why mess with bluetooth or dedicated connections when you can get the chrono to send serial data via TRSS cable thru the headphone jack?

[M852]

Why mess with bluetooth or dedicated connections when you can get the chrono to send serial data via TRSS cable thru the headphone jack?

Because wireless goes to 11.

Seriously, though, the Caldwell solution you linked is a dedicated connection (from the chrono to the mobile device), so it's no different from the DIY cable for the ProChrono Digital other than the interface at the device (USB vs. 3.5mm multi-jack). Also looks like the Caldwell solution is one-way which means you could get data off the chrono but not control it. You can do both with the wired & wireless DIY options for the ProChrono Digital.

Having said all that, I really like what Caldwell has done because more features means more competition. Maybe this will get CED and the other chrono manufacturers off their posteriors and building these solutions as affordable features so we won't have to.

[pobro]

Why would you need to control a chronograph? What would you tell it to do that it doesn't already do? As long as it takes readings and sends them to a smartphone where they can be seen, recorded, analyzed, saved, and exported that's plenty.

Have you ever seen a 15' USB cable?

Yes, it certainly should create some buzz amongst the competition.

[M852]

Why would you need to control a chronograph?

To change the string displayed, delete shots, delete strings, etc.

What would you tell it to do that it doesn't already do?

Nothing. However, the wired & wireless DIY options here allow you to choose where you want to "tell it to do."

As long as it takes readings and sends them to a smartphone where they can be seen, recorded, analyzed, saved, and exported that's plenty.

Some of us find greater value in being able to do that and control the chrono remotely.

Have you ever seen a 15' USB cable?

Yes. However, the ProChrono uses a standard 3.5mm stereo cable with a serial-to-USB converter on the end for its wired control connection.

[chaoticmachinery]

Hello,

I've been trying get past the first step of configuring my BT2S. Unfortunately, all I have access to right now is a PL2303HX USB to Serial adapter. I've wired it up to the BT2S slave and tried that 'AT' command. I get absolutely nothing back. I tried switching the TX & RX around. Still nothing.

I have the serial set to 9600 8N1.

BTW I know the cable works. I used it to fix a Foscam issue the day before.

Thoughts?

Thanks,

CM

[M852]

I've been trying get past the first step of configuring my BT2S. Unfortunately, all I have access to right now is a PL2303HX USB to Serial adapter. I've wired it up to the BT2S slave and tried that 'AT' command. I get absolutely nothing back. I tried switching the TX & RX around. Still nothing.

I have the serial set to 9600 8N1.

BTW I know the cable works. I used it to fix a Foscam issue the day before.

Thoughts?

I vaguely recall reading somewhere that connecting to HC05/06 chipsets with anything but CP2102 based converters is sketchy. Still, make sure you've got your wiring correct (i.e., TXD → RDX, RDX → TDX, etc.) and make sure the COM port you're connecting to in your terminal emulator is the COM port assigned to the USB converter. If that's all correct, try using a different terminal emulator. I tried several and at least one of them balked with the BT2S no matter how I configured it. Also, make sure the BT2S is in seek mode while configuring it - i.e., make sure it is not paired while trying to change the configuration.

If none of that works, try a CP2102 based converter. If you're patient, you can get one on ebay from the pacific rim for less than $2. If you want it sooner, you can get one for ~ $5 from a US seller.

Post your findings. It may help some other folks out.

[Doug G]

Hello,

I've been trying get past the first step of configuring my BT2S. Unfortunately, all I have access to right now is a PL2303HX USB to Serial adapter. I've wired it up to the BT2S slave and tried that 'AT' command. I get absolutely nothing back. I tried switching the TX & RX around. Still nothing.

I have the serial set to 9600 8N1.

BTW I know the cable works. I used it to fix a Foscam issue the day before.

Thoughts?

Thanks,

CM

I remember reading somewhere on here that the RX line (line containing data coming from the ProChrono) should be tied to ground with a 10K resistor. I've encountered that myself when trying to read data from the ProChrono with an Arduino. I was getting no incoming data even though I could send commands out until I put the resistor in, then it all worked. Perhaps something to try if all else is failing. Might also try 1200 baud, as that's the native ProChrono serial speed acording to the published specs.

Edited April 19, 2014 by Doug G

[M852]

Hello,

I've been trying get past the first step of configuring my BT2S. Unfortunately, all I have access to right now is a PL2303HX USB to Serial adapter. I've wired it up to the BT2S slave and tried that 'AT' command. I get absolutely nothing back. I tried switching the TX & RX around. Still nothing.

I have the serial set to 9600 8N1.

BTW I know the cable works. I used it to fix a Foscam issue the day before.

Thoughts?

Thanks,

CM

I remember reading somewhere on here that the RX line (line containing data coming from the ProChrono) should be tied to ground with a 10K resistor. I've encountered that myself when trying to read data from the ProChrono with an Arduino. I was getting no incoming data even though I could send commands out until I put the resistor in, then it all worked. Perhaps something to try if all else is failing. Might also try 1200 baud, as that's the native ProChrono serial speed acording to the published specs.

He's working on the connection between the USB-to-TTL module and the Bluetooth module (vs. the Bluetooth module to ProChrono connection).

[chaoticmachinery]

I've been trying get past the first step of configuring my BT2S. Unfortunately, all I have access to right now is a PL2303HX USB to Serial adapter. I've wired it up to the BT2S slave and tried that 'AT' command. I get absolutely nothing back. I tried switching the TX & RX around. Still nothing.

I have the serial set to 9600 8N1.

BTW I know the cable works. I used it to fix a Foscam issue the day before.

Thoughts?

I vaguely recall reading somewhere that connecting to HC05/06 chipsets with anything but CP2102 based converters is sketchy. Still, make sure you've got your wiring correct (i.e., TXD → RDX, RDX → TDX, etc.) and make sure the COM port you're connecting to in your terminal emulator is the COM port assigned to the USB converter. If that's all correct, try using a different terminal emulator. I tried several and at least one of them balked with the BT2S no matter how I configured it. Also, make sure the BT2S is in seek mode while configuring it - i.e., make sure it is not paired while trying to change the configuration.

If none of that works, try a CP2102 based converter. If you're patient, you can get one on ebay from the pacific rim for less than $2. If you want it sooner, you can get one for ~ $5 from a US seller.

Post your findings. It may help some other folks out.

I appreciate the suggestions. The CP2102 I ordered from Hong Kong finally came in the mail yesterday and I was able to get it to work.

[M852]

I appreciate the suggestions. The CP2102 I ordered from Hong Kong finally came in the mail yesterday and I was able to get it to work.

Very good. Glad you got it working.

[chaoticmachinery]

Good day,

I wired everything up to the docs posted. If I hook up the batteries (without plugging it into the chrono), should the bluetooth slave light start blinking? I don't see any blinking lights.

I did use the Kycon STX-3100-9C jack and I plugged in a 1/8" stereo cable into the jack.

Also, I was thinking it might be nice to wire up an LED to show the unit has power (and on). What should I use and where should I wire it into? My guess is it would get wired into the VIN line shown on page 6.

Thanks,

CM

[M852]

I wired everything up to the docs posted. If I hook up the batteries (without plugging it into the chrono), should the bluetooth slave light start blinking? I don't see any blinking lights.

I did use the Kycon STX-3100-9C jack and I plugged in a 1/8" stereo cable into the jack.

If you've wired up the Kycon STX-3100-9C as shown in the post above, then yes, the LED on top of the Bluetooth module will blink rapidly when one end of the 1/8" cable is plugged into the Kycon STX-3100-9C and the other end left unplugged. I don't think it goes solid until it's communicating with the PCRemote software.

Also, I was thinking it might be nice to wire up an LED to show the unit has power (and on). What should I use and where should I wire it into? My guess is it would get wired into the VIN line shown on page 6.

I actually thought about that, but I didn't have any easy answers to the questions it raised (and I'm not an EE) so I punted. Having said that...

Wiring it between the Kycon STX-3100-9C and the VIN on the voltage regulator would make sense to me. But, you'll have to decide whether you want to put it in-line or ground it out on the common ground. Also, you may need to put a resistor in there somewhere depending on the type of LED used. I'd love to hear any ideas or experiences for doing this if anyone has them.

[chaoticmachinery]

If you've wired up the Kycon STX-3100-9C as shown in the post above, then yes, the LED on top of the Bluetooth module will blink rapidly when one end of the 1/8" cable is plugged into the Kycon STX-3100-9C and the other end left unplugged. I don't think it goes solid until it's communicating with the PCRemote software.

Turns out I had it wired right. Dummy me had some electrical tape covering up the LED on the bluetooth slave. I had solder the resistor to the bluetooth slave and used electrical tape to temporarily cover the resistor. Plus, I thought the LED was closer to the antenna. Go figure.

Also I installed the LED. Here is what I did. Please keep in mind I am absolutely a beginner with this stuff. I based my solution on what I did to turn a PC power supply into an electronics test bench power supply. That solution had 5 VDC going to a LED when it was turned on.

Radio Shack parts:

1) LED Part # 276-0036 (5VDC) Note: This red LED blinks.

2) 330 Ohm 1/2 watt carbon-film resistor Part # 2711113

Solder the resistor on to the positive side of the LED. Then I connected the resistor to the wire that was going to VCC on Bluetooth slave. Connect the negative side of the LED to the battery ground. For any of the bare wires I put some heat shrink on it. Just keep that in mind as you put it together.

Regards,

CM

Edited April 28, 2014 by chaoticmachinery

[M852]

Turns out I had it wired right. Dummy me had some electrical tape covering up the LED on the bluetooth slave. I had solder the resistor to the bluetooth slave and used electrical tape to temporarily cover the resistor. Plus, I thought the LED was closer to the antenna. Go figure.

Hate it when I do that kind of stuff. The first note in the Troubleshooting section is there because I had to remind myself, not because I thought someone else needed it.

Also I installed the LED. Here is what I did. Please keep in mind I am absolutely a beginner with this stuff. I based my solution on what I did to turn a PC power supply into an electronics test bench power supply. That solution had 5 VDC going to a LED when it was turned on.

Radio Shack parts:

1) LED Part # 276-0036 (5VDC) Note: This red LED blinks.

2) 330 Ohm 1/2 watt carbon-film resistor Part # 2711113

Solder the resistor on to the positive side of the LED. Then I connected the resistor to the wire that was going to VCC on Bluetooth slave. Connect the negative side of the LED to the battery ground. For any of the bare wires I put some heat shrink on it. Just keep that in mind as you put it together.

Excellent! What power source are you using? I wonder how many mAh the LED uses and how that would affect battery life.

[chaoticmachinery]

Also I installed the LED. Here is what I did. Please keep in mind I am absolutely a beginner with this stuff. I based my solution on what I did to turn a PC power supply into an electronics test bench power supply. That solution had 5 VDC going to a LED when it was turned on.

Radio Shack parts:

1) LED Part # 276-0036 (5VDC) Note: This red LED blinks.

2) 330 Ohm 1/2 watt carbon-film resistor Part # 2711113

Solder the resistor on to the positive side of the LED. Then I connected the resistor to the wire that was going to VCC on Bluetooth slave. Connect the negative side of the LED to the battery ground. For any of the bare wires I put some heat shrink on it. Just keep that in mind as you put it together.

Excellent! What power source are you using? I wonder how many mAh the LED uses and how that would affect battery life.

3 AA batteries.

As to battery life, I guess I will have to hook it up for a day and see how long it lasts. I shot for the blinking LED as I was thinking it it should end up using less than a solid LED. But then again since this stuff is all new for me, I could be looking at it wrong.

[rtp]

Deleted after some discussion.

Edited April 30, 2014 by rtp

[M852]

I've managed to get the lite version done and working on my phone, but before running the program you must pair your Bluetooth device using the phones own Bluetooth pairing feature, then run the program and select the paired item. Once selected, it should say 'Connected successfully' after a few seconds, then press the 'Start' button and you should see the last shot in that string displayed on the screen, if not, something is wrong either with the compatibility of the app on that phone or a Bluetooth hardware issue. From here each shot fired through the ProChrono should be displayed on the phone.

If any errors occur let me know and ill look at them in due course, also let me know your thoughts and any improvements you think would be good to add, this doesn't mean you'll get an upgrade anytime soon, but it will be something I'll work on slowly.

I've also added a little extra feature Enjoy!!!!

Main.zip

Got an error trying to unzip the file(s). Repost or PM the file to me?

[KernelPanic]

The BT2S hates me! Here's what I've done so far: Using a solderless breadboard and a 5 volt power supply, I connected the ProChrono to a MAX232 TTL to RS232 chip. Both the ProChrono software and a terminal program work fine. I then set the BT2S to 1200 baud. I crossed RX and TX for a loopback and the terminal set to 1200 baud echoed the characters back correctly. I connected the BT2S to the ProChrono, connected the 10K pull down resistor to ground and nada with both the ProChrono software and the terminal. Now here's the strange part. Using the terminal, it would not perform a change string operation, but if I connected a 1K resistor from the BT2S TX terminal to +5V the change string command would work. Still no joy on any output from the ProChrono. It would seem to be a level issue. I am using V1.06 of the module(I tested two of them), but I have noticed that any examples I have seen are using V1.05. I wonder if they messed the levels up on the new revision? Any ideas would be much appreciated.

[M852]

Now here's the strange part. Using the terminal, it would not perform a change string operation, but if I connected a 1K resistor from the BT2S TX terminal to +5V the change string command would work. Still no joy on any output from the ProChrono.

Make sure the 10k resistor is between the TXD (tip) and GND (sleeve) coming from the ProChrono side (on the BT2S side it would be between the RXD and GND).

Take a look at the Wired Connections troubleshooting section at the end of the guide in the first post. I put some steps in there that may be helpful given what you've described.

If you're still having trouble after that, I would get in touch with Virtuabotix tech support. They were solid gold when I was building and troubleshooting the prototype.

[KernelPanic]

Now here's the strange part. Using the terminal, it would not perform a change string operation, but if I connected a 1K resistor from the BT2S TX terminal to +5V the change string command would work. Still no joy on any output from the ProChrono.

Make sure the 10k resistor is between the TXD (tip) and GND (sleeve) coming from the ProChrono side (on the BT2S side it would be between the RXD and GND).

Take a look at the Wired Connections troubleshooting section at the end of the guide in the first post. I put some steps in there that may be helpful given what you've described.

If you're still having trouble after that, I would get in touch with Virtuabotix tech support. They were solid gold when I was building and troubleshooting the prototype.

It's definitely a V1.06 issue. I cant seem to post the link, but I read an article that explains why I had to add the pull up resistor to get the ProChrono to receive using the V1.06 board. I contacted Virtuabotix and they are aware of the problem, but they offered to send me a prototype level shifter for $5 plus shipping. Not a happy camper about that! It seems these units don't work correctly at either 5V or 3.3V. I don't mind adding a couple of resistors, but I can't figure out the correct value for the ProChrono tip. 10K does not work. It might not event be a matter of simply a pull down resistor with this new revision.