I've got a Shooting Chrony which has a serial output.  I was looking at putting a TTL-to-USB adapter so I can put the data directly to a laptop, but it looks like using a bluetooth adapter may be pretty much the same level of complexity.  I'd need to wire a 3.5mm audio plug to a $6 adapter, along with a small circuit to provide power.  And I think at that point I should be able to put it on one of the computer COM ports which would then be accessed with a terminal console (think that's the name) sort of program.  I'm imagining it'd be like manually driving a dial-up modem in the old days--the commands are all published.

Anyone tinker with anything along these lines?


Plea for EE help:  Need to put 3.6 - 6V onto the bluetooth card for 30mA?    See post below.

I haven't but I'd love to be able to do this with my Caldwell crono.

If I remember correctly, both the serial to USB and serial to bluetooth adapters use virtual COM ports, so it'll pretty much be the same.

The biggest pain in the ass is if bluetooth grabs a different virtual COM port each time, then you'll have to use device manager or some other utility to find out which one to access in order to retrieve the data.

http://www.competitionelectronics.com/product/bluetooth-adapter/

I have the chronograph but have not bought the adapter.  I usually chrono in situations where I can go cold and go down range as needed.

I have the ProChrono digital and have purchased the serial adapter but have not been able to get it to communicate.

Vince

Spent $7 on a ttl/rs-232 HC-06 transceiver board.  Update maybe next week when it shows up.

Wiring should be very simple.  I have only vague notions of how things will go after that.

I need 3.6-6v supply for the bluetooth card.  Can I just put a voltage divider (i.e. simply a pair of 4.7k resistors) on a 9v battery?  I do have a OPA2134 opamp lying around.  Or I could just do a 3 pack of AAA's from a ChinaFreight flashlight.  I have a good assortment of resistors and caps.  Bluetooth draws 30mA

I'm mechanical by nature.

Don't use a voltage divider, they're better for a reference voltage, but not something drawing current.

Get a 4 x AA holder - that'll get you 6.0 V and you won't lose anything due to conversion losses of a linear or switching regulator.

Well I got it to pair, but the chrono is not responding (i.e. I can't type anything in on the terminal emulator).  I'm wondering if I'm missing a piece of hardware in the equation.  I literally have a headphone jack soldered to the goes-ins-goes-outs, the bluetooth card, and some batteries to put 5v to the card.


I do notice now that the chrony works on 5v logic signals and the bluetooth card does 3.3V.  Maybe thats it.  I can use a voltage divider on the bluetooth receive pin but not sure what to do on the send pin to step up from 3.3 to 5v.  The internets when googled assume I have some broad and comprehensive understanding of electrical stuff and how to select parts.

sparkfun and adafruit sell all the shit you need, including 3.3 to 5v bidirectional level shifters.

i would just go with an ftdi usb to ttl serial cable which can be purchased in a 5v or 3.3v version.

screw bluetooth for this

check out this thread on Brian Enos, it might help you along

http://forums.brianenos.com/index.php?/topic/176086-diy-bluetooth-interface-for-prochrono-digital/

WRT the 5v-3.3v conversion, there are level shifters made specifically for that purpose, Ti makes them.  

I've something similar to this one in the past:

http://www.ti.com/product/txb0108