Trouble reading SPI flash with CH341A [aka changing name of a bluetooth adaptor] - Page 1
Forum section: electronics / beginners

author: juris.d
author_rank: Contributor
timestamp: June 27, 2017, 03:44:43 pm
content: Good day all.My 2nd topic in this forum and I am looking for any help.Short description:I have a Chinesium 30pin bluetooth A2DP adaptor that I want to use on my out of date docking station/speaker, however, I would like to change the name on it.adaptor -https://www.ebay.co.uk/i/262597880691?chn=ps&dispItem=1&adgroupid=52097426788&rlsatarget=pla-382293677207&abcId=1058846&adtype=pla&merchantid=109712317&poi=&googleloc=9046080&device=c&campaignid=863276125&crdt=0Currently it is named as "I-WAVE", but I would like something more personalised.When cracking it open, there are a few devices, but my main focus is on the 8pin flash device that has the markings - T25S40 BG16n7 B13968. I have narrowed it down to a generic 4MBIT SPI NOR flash by Brightmoon Electronics.Datasheet:http://bmsemi.com/upload/file/20160317/14582047381395063.pdfSince I have had my youth playing with Hex editors, I had an idea of reading the flash and opening it up in HxDen, looking for the name and just changing it.I bought the cheapest available EEPROM programmer, as I had no intention in investing a lot of money in to this project, but ran in to some trouble. I cannot seem to read the flash properly.Reader -http://www.ebay.co.uk/itm/CH341A-24-25-Series-EEPROM-Flash-BIOS-USB-Programmer-SOIC8-Clip-On-Board-UK-/162557028178?epid=1390692406&hash=item25d9276752:g:vG8AAOSwCQZZCi3SI bought the exact same reader with the test clip. Tried several drivers, several methods of using it, but it always produces an unsatisfactory result.While the reader does not recognize the flash directly, there is an option of selecting a generic 25S40 flash device. When reading it, there are no recognizable characters in the binary. Every time I read it, it seems to produce the same result and checksum, so I am a little baffled here.The dump of the Flash device can be downloaded below, if anybody cares to look at it.https://files.fm/u/ayjjwnn8It's a 512KB file. Does not contain any viruses (as my ESET32 is dropping a warning) and comes direct from my desktop.I have seen somebody on the internet reading a similar device with an Arduino, but since there are no concrete details to his work, I am stuck with this as well.http://waihung.net/bluetooth-audio-mod-on-car-cassette-player/Can anybody lead me the right way? What am I doing wrong here? Is there a complete tutorial on how to read and program EEPROM/FLASH devices via Arduino?I would like to dump the contents of the device, change the name (I know it has to be same character length) and flash it back in to the device.Any help appreciated.Thanks a lot!

author: bktemp
author_rank: Super Contributor
timestamp: June 27, 2017, 03:52:30 pm
content: The bin file looks good to me.I can see some short text strings like ID3, TCON and BTEX. So the data are not random garbage but maybe encrypted firmware data.

author: juris.d
author_rank: Contributor
timestamp: June 27, 2017, 04:01:06 pm
content: Thank you for your answer.Do I take it as a hint, that this is encrypted and there is not much I can do about it?A random idea, but since all of these are similar, would it be possible to flash this thing with something random from a similar device? I appreciate, that the components have to be similar, but maybe worth a shot.