Megajolt Android tuning app

Discussion on Future Megajolt hardware / software upgrades.

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brentp
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Post by brentp »

Note, you will need to ensure the bluetooth module's baud rate is set to 38,400. this might've been mentioned earlier in the thread..

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jestes
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Post by jestes »

Good point Brent. I don't think that part was mentioned earlier in the thread. I talked about the hardware and the Android application, but not configuring the module itself.

capri_turbo
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Post by capri_turbo »

I'll try that if I can ever get a bluetooth connection to talk to it. Trying a terminal emulator on the phone later.

capri_turbo
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Post by capri_turbo »

Quick question regarding changing the baud rate. I can't do it over the bluetooth connection as it needs to be in AT mode, so can I do it through the megajolt serial port if I pop the mcu out for safety?

brentp
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Post by brentp »

Yes, that would work in theory. Keep us posted!
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capri_turbo
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Post by capri_turbo »

Some good news. Using the MJLJ hardware with the MCU removed I can talk to the Bluetooth module via the serial port on the MJLJ. I get OK when I type AT and have been able to change the baud to 38400 using the AT+BAUD6 command and get the response OK38400. I have then gone back in using PuTTy at 38400 to check comms and AT returns OK so it must all be wired correctly.

I have powered down the module, put the MCU back in the jolt and have paired the phone again, connected the app and no data. Have I missed something?

Col

jestes
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Post by jestes »

In the app, did you go to the Comms Settings menu and select the blue tooth pairing to use? I think the app will warn you if you don't but that is the only think I can think of that might be wrong. When do you get the error, when you click Connect?

capri_turbo
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Post by capri_turbo »

Here's what I've done so far.

Nice neat connector carrying 5V, Gnd, Tx and Rx all hard wired inside the MjLj:

Image

HC-06 Bluetooth module wired into a small project box:

Image

Fitted up and looking very neat:

Image

Test bench wiring looms (currently using the MjLj hardware to gain access to the BT modules serial port):

Image

Sadly still no comms to the phone app :( but it looks the part...

capri_turbo
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Post by capri_turbo »

Selected and paired to the module. App connects and modules LED stops blinking and stays solid.

Gauges all sat at "0" permanently. If I disconnect the app it says connection lost for about 5 minutes and I usually have to restart the phone to get rid of it, however it will reconnect quite happily but with no comms.

jestes
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Post by jestes »

What version of the hardware and firmware are you using? It has only been tested with the latest.

brentp
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Post by brentp »

Ah. V3 controller requires 9600 baud. Which is weird because that's the default baud rate of those BT modules. Maybe check if RX / TX needs to be swapped?
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capri_turbo
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Post by capri_turbo »

V3 hardware with 3.3.1 firmware.

Col

capri_turbo
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Post by capri_turbo »

Tried swapping Rx and Tx with the baud as received which was 9600, same result. I'll have to swap the baud back to 9600 then :oops:

jestes
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Post by jestes »

Is the comms protocol the same for V3 and V4?

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Post by brentp »

IIRC it is different in areas. It has been so long :)
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