To obtain your registration code or if you are not able to recover your MHH account, kindly contact [email protected]
MHH is in-compatible with Internet explorer!
Thread Rating:
  • 22 Vote(s) - 2.55 Average
  • 1
  • 2
  • 3
  • 4
  • 5

ELM327 Bluetooth mini v2.1 with STM32F042

1
what about this? stm32f042 under the black blob?

[Image: mini-obd2-bluetooth-adapter-innenleben.jpg]

[Image: file.php?id=1862]

by the way, the 2 pictures are the same pcb but the 2nd have some different components: missing 120 ohm CAN termination resistor, and 8a619 12v->3v regulator for both 3v CAN transceiver and bluetooth chip (instead of 12v->5v->3v regulators for 5v CAN transceiver and 3v bluetooth chip)

i have 2 units of the 2nd type but they only pair to smarphone's bluetooth, no connection with any app, elm327 identifier neither...for example, with scanmaster i always get "Bluetooth device 00:1D:A5:68:98:8D not found"

SOLVED: DELETED ALL BLUETOOTH SAVED DEVICES IN SMARTPHONE, THEN IT WORKED
BUT THE DEVICE IS SOOOOO SLOW, WORST OF ALL I GOT
DON'T BUY ANY DEVICE WITH A BLACK BLOB!!
EDIT: WITH OTHER SMARTPHONE IT WAS FAST THOUGH


[Image: UTB8R.a6XHPJXKJkSafSq6yqUXXa6.jpg]
[Image: UTB8ZtDHc9nEXKJk43Ubq6zLppXah.jpg]

what's the problem? how could i fix it? SOLVED

pcb is a mix of these:

[Image: post-202337-0-87074300-1470916042.jpg]

---
[Image: post-202337-0-76775500-1468326457.jpg]

---
THIS IS MOST SIMILAR, BUT WITHOUT ATMLH532.
MY DEVICE CHECKED: K-LINE TERMINATION IS OK: 45K + 20K RESISTORS

[Image: post-202337-0-56621700-1471456426.jpg]

---
[Image: post-202337-0-29740500-1470163977.jpg]

---
NEW:
---
UPDATED: THIS IS SCHEMATIC AFTER TESTS
[Image: attachment.php?aid=197720]

ELM327 IDENTIFIER
(TOOK A LOT OF TIME TO CONCLUDE TEST, IT IS A VERY SLOW DEVICE)
[Image: attachment.php?aid=202790]

Attached Files Thumbnail(s)
       
Thanks given by: 153771739 , plasticman1971
2
It is so cheap this "tool", i wouldn`t even think to repair it ! couple bucks and get a new one in the postal mailbox.
Thanks given by:
3
I know, got other working units, the point is to find out whats wrong for all owners, if its a matter of electronics or programing, if someone have some working unit or all are defective etc, maybe its unrepairable or just removing a resistor... just the joy of learning SOLVED

Btw,I am trying CAN bus, but that is not the point, no app is capable of making a connection with the adapter, it is only possible to pair adapter with smartphone (password 1234) but no connection to any app, Bluetooth chip is working but elm327 chip is not working SOLVED

Attached Files Thumbnail(s)
   
Thanks given by: 153771739 , plasticman1971
4
I have one blu adapter quasi similar as yours, it has 2 pcb inside, the upper one is making OBD connections, mains 12v>5v ( 78M05 ), and the lower one is the interesting one has 3LEDs, TJA1040 ( CAN transceiver ), BK3231Q ( blu comm chip ) and the one that suits you, uP MCP2515 so it is not clear which chip do you have there under the black blob
The 2 pcb are solder together by 2 rows of wires so i can`t disconnect them to photo them, anyway it is a broken adapter, now it is connecting OBD and also blu with android Torque apk but is is discarding and flooding CANbus with thrash, on dash ABS it is on/off no reason, speedo and revs are swinging out of order.
Paid 5$ << postage china - europe included ! >>, worked for 5$ meaning 2 weeks !
Thanks given by: 153771739
5
yours is a different device, i am interested in this:
(IT DOESN'T SUPPORT SAE J1850 PWM/VPM - OBDII PINS 2+10)
(IT DOESN'T WORK WELL, VERY SLOW, WORST DEVICE)
[Image: attachment.php?aid=197701]


i also got another v2.1 with elm327 code inside the bluetooth ARM chip bk3231q:
(IT DOESN'T SUPPORT SAE J1850 PWM/VPM - OBDII PINS 2+10)
(IT DOESN'T SUPPORT ISO 9141-2 L-LINE - OBDII PIN 15)
[Image: 7115826.jpg]
[Image: attachment.php?aid=202792]


and also v1.5 supporting all elm327 commands upto 1.4 (reported by elm327 identifier) like this:
(IT SUPPORTS ALL OBDII PROTOCOLS)
(THIS IS THE BEST AND ONLY I WOULD RECOMMEND, AND JUST ABOUT 5€)
[Image: UTB8zahXXT_IXKJkSalUq6yBzVXaJ.jpg]
[Image: UTB8OhM_XrnJXKJkSahG760hzFXaD.png]


here are all elm327 bluetooth types: (video in russian language without subtitles Sad )
https://www.youtube.com/watch?v=TeeUCoppzJc
and great info here: (use translator)
http://forum.cxem.net/index.php?/topic/1...%B7%D0%BE/

Attached Files Thumbnail(s)
       
Thanks given by:
6
differences between 3.3v and 5v devices:

[Image: attachment.php?aid=199413]

[Image: attachment.php?aid=199414]

it seems to me the idea of 120 ohm termination resistor for canbus is taken from this canbus board:

[Image: attachment.php?aid=199415]

[Image: attachment.php?aid=199416]

[Image: attachment.php?aid=199417]

source: http://www.farnell.com/datasheets/1838662.pdf

also this board uses 120 ohm resistor between pin 6 and 7 of canbus transceiver, but through a transistor for reset???...
http://www.mouser.com/ds/2/268/51757a-220349.pdf

and also this ebay arduino canbus module:
[Image: Can-board-Pin-Outs.png?resize=666%2C333]

[Image: Arduino-CAN-Bus-Module-Schematics.png?resize=768%2C533]

source: http://henrysbench.capnfatz.com/henrys-b...chematics/

[Image: 3-unids-Bus-MCP2515-CAN-TJA1050-M-dulo-r...CU-ARM.jpg]

Attached Files Thumbnail(s)
                   
Thanks given by: 153771739 , plasticman1971
7
k-line solution:

[Image: attachment.php?aid=199526]

Attached Files Thumbnail(s)
   
Thanks given by: neoleo

Possibly Related Threads…

 
Replies: 2
Views: 130
09-13-2019, 06:44 PM
 
Replies: 0
Views: 72
09-03-2019, 08:51 PM
 
Replies: 1
Views: 258
06-29-2019, 06:24 PM
 
Replies: 41
Views: 15,795
06-25-2019, 06:36 AM
Ford
Replies: 0
Views: 256
06-02-2019, 01:51 AM
Users browsing this thread: 1 Guest(s)