MS1 V2.2 board Bluetooth

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MS1 V2.2 board Bluetooth

Postby robocog » Sat May 07, 2016 12:58 pm

Hi chaps/chapesses

I have some HC05/HC06 boards spare and fancy going wireless for adjustments/monitoring

I /think/ I want to use it externally and easily removable via the serial port rather than using it internally and hooked direct to the MCU's TTL RX and TX

I just want to check I am on the right tracks - I have also ordered some MAX232 chips which will possibly be with me in the next month or so :D

I /should/ be able to use the MS's DB9 serial port VCC (5v)on pin 1 and the grounds on pins 5 and 9 to supply power the HC05's module and MAX232 chips direct from the port safely?

Using the MAX232 board between the DB9 serial port and bluetooth module /should/ convert TTL to RS232 and RS232 to TTL? (as long as I cross TX with RX both sides)

If not I guess I'll just emulate what I have seen and install the BT module internally and cut a slot for the antenna to dangle through :D

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Re: MS1 V2.2 board Bluetooth

Postby robandnoah » Sat May 07, 2016 4:47 pm

that should work fine. You will need to convert the 5v ttl output from the max232 to 3.3v to feed the HC05 rx input. A voltage divider will suffice.
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Re: MS1 V2.2 board Bluetooth

Postby robocog » Tue May 10, 2016 1:43 am

Thank you
Ok that sounds straightforward enough

Will try to update with pics when the max232 boards arrive

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Re: MS1 V2.2 board Bluetooth

Postby andy198712 » Mon Jun 27, 2016 2:02 am

I'd be interested in what you do too as I'm looking at going Bluetooth on my v2.2 too (that's a lot of to's)

Just plugging into the serial would be ideal, clipping the pin kinda means you can't then use the cable does it?
Must be do able as the efi plugs in there.....

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Re: MS1 V2.2 board Bluetooth

Postby robocog » Mon Dec 11, 2017 7:03 am

Got the bluetooth module configured
(named it "megasquirt" set the pin code and set the baud rate to 9600)
All drama free

I can connect to the bluetooth - and looping rx to tx echoes back from a terminal - can clearly see the signals on the scope
Again all good

I then got to wiring the max 232 board - this is where it all falls over
Killed two out of 3 of the boards (I assume) and one other is acting strange
I have probed with the scope to try and "see" what it is trying to do
(but not had much luck

Originally I soldered leads onto the wee little serial to ttl boards
(they are double sided and not particularly clear as to what goes where - at least not to a novice)

The boards on the back have the following markings
RS232 <-> TTL
> -
< +
+ <
- >

so I wired it as RS232 on the left
to 3.3v psu +
to signal gnd and psu gnd

and on the right for ttl (so I could try and see signals to a usb to ttl board)

I opened a terminal and probed to "see signals" coming in/going out (whilst typing in a terminal)
In the confusing and haphazard rats nest of wires something went horribly wrong
the usb ttl RX led was constantly lit and I assumed I had killed it so I desoldered that one and this time soldered some header pins to number 2 of the wee rs232 to ttl boards

I tested loopback (RX to TX) via a terminal on the usb to ttl and thankfully I hadnt killed that and it was happily repeating what I sent

Using header pins on the rs232 to ttl boards proved just as tricky to get good solid readings/ results
(pins and flying leads were not stable and I had to bend the pins slightly to make contact)
I soldiered on and decided to hook it up to my MS1 V2.2 without probing of pins and fired up msdroid

It tried to establish contact but was coming back saying the signiature was not known "Q"

It was late and I shouldnt have carried on ...but I did and I cannot remeber all the combinations I tried
(hooking power and grounds to both ends of the rs232 ttl boards rather than just the rs232 side - i tried just the ttl side for power...yea...)
I gave up on that board and started afresh with the 3rd and final rs232 to ttl board - pinned just the bottom end
I put it in a breadboard so we didn't have any more incidents
I could "see data" on the scope going out from the bluetooth TX
I thought I could "see data" going out from the TTL
I thought I had it cracked...but msdroid just sits there forever

I did test the MS1 with the std rs232 straight to the PC and it still works
I wiggled wires on the breadboard and to the MS's com port (still the same crappy flying leads)
and managed to snap a leg off the max232 board in the process

so that is 3 killed max232 boards
(I also killed C30 4.7uF tantalum on the MS board when I plugged in the wrong PSU to the jimstim)
Have ordered a replacement tantalum and looking at buying a ready built bluetooth to rs232 as my cobbled conversion from ttl to rs232 is beyond me
(thought it would be straightforward)

Will update a bit sooner than last time hopefully
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Re: MS1 V2.2 board Bluetooth

Postby robocog » Wed Dec 13, 2017 9:20 am

Had quite a successful day

I started again from scratch with a maxim max233cpe I had laying around
got it wired as per the datasheet and it works!
so I was either wiring the little chinese 3232 boards incorrectly or doing something wrong

Then the postman arrived with the neat little rs232 to ttl board I ordered in the week
Got busy gutting a Duplo brick (because the Mrs won't allow me to get a 3d printer), added a lipo and a charging circuit and a switch

Can see the LEDS for charge and bluetooth through the body of the brick so I sealed the bottom off with hotglue and a cut up Amazon prime 30 day trial card that had expired

All done, not the neatest, but it functions :D

IMAG1210 (Medium).jpg

IMAG1209 (Medium).jpg

IMAG1208 (Medium).jpg

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