Hello i know there is a few working ways to do this already out there but this is the first one that i know of that are based on a really cheap module(2-3usd), and require no modification on the module.
This is the module, the chip on there is a bk3231:
All you need to make a Bluetooth pro mini upload adapter is a few components you most likely already have around 4 10k resistors a npn transistor a 0,1uf cap pin header and some prototype board.
This bt module have a mcu-int pin that go high when the bt module connects with something, this is what i use to reset the pro mini.
first you need to set the baud rate just connect the module to whatever serial module you prefer, if its a 3.3v level connect directly if not use voltage divider on the rx pin on the bt module.
Set the serial monitor for 9600(standard speed from factory) and cl&nr and write AT + BAUD7 to set the baud rate to 57600 (programming speed for pro mini)(tx on bt to rx on serial....)
The angled pins are for vcc, the pro mini im using have a protection diode so i had to bypass that.
some pro mini have it some do not, and some have the pin order completely reversed so take care when you connect it all up.
(I have a small led on the mcu-int, this is not really needed and is not in the schematic)
So best of luck and if you try this please let me know how it goes and if you have ideas abut improvements.
aisc:
I would not mind something like this for an ATTiny85...
Not possible as I understand it. The bluetooth is uploading the sketch to the Pro Mini via serial. You can do this with an atmega328 because it has already been programmed with a bootloader. You can't have a bootloader on an attiny85, not enough ram/flash/whatever. So attiny85 can only be programmed via SPI, which the bluetooth module cannot do.
However, there are some attiny chips, such as the '841, which can be programmed with a bootloader and then subsequently sketches can be uploaded via serial.
If someone had the Bluecore devkit from CSR, a firmware could be written that made the Bluetooth-module look like an AVRISP or similar device, and through that, program the chip. Having the SDK for the Bluetooth-module opens up an extreme amount of possibilities, as there is much power in that ARM SOC they are using. Heck, even no need for the Attiny if you go that far!
I have tried this on win 7 and 8.1, i have never used os x, so im afraid im wont be mutch help there, I guess you have already double and triple checked the Connections but check that the Connection is like in the diagram one more time. and make sure you have the vcc bypass in Place if you have a pro mini with protection diode, the module will light up anyway but without the vcc bypass it wont work.
Another thing to think abaut, atleast for me i get 2 serial ports when i connect to this over Bluetooth and the annoying part is sometimes its the higher number of the 2 and sometimes the lower one that is the port for uppload....
mayby a Picture of the setup will help me thing of something!?
//s
