Hi, I have a picaxe 18m2 and a chi035a board and i would like to know if i have any possibility to pass information via bluetooth from a mobile to the picaxe, i'm just interested in the hardware, i'm not asking for software.
I have seen sparkfun.com site and I cant decide which module choose. Would https://www.sparkfun.com/products/8497 that module work on my idea, otherwise could you say me which one would i need?
I really thank any help and I hope you have a solution to my project.
A few things about the cheap BT modules from eBay you should know:
The BT Modules can’t be configured from the Bluettoth side, only from the serial UART side. This could be making trouble if the module is wrong configured. From the spec sheet it should work as slave, 38.4kBaud. This should work for you. If you need to change the setup, you will need a USB/UART module to connect the BT module on a PC and change the setup from a terminal program.
Be warned. Some eBay sellers sell similar modules with wrong or without any specs. See this thread
BTW. The BlueSMiRF can be configured from the Bluetooth side.
Your picaxe is a 5v system and will output whatever it is getting for a Vcc. This is of course, in its “5v mode” (the m2’s can also be run at 3.3v). In either case, again, your digital outputs will send out whatever the Vcc is.
The key words you need to focus on here are “level shifting” and if your bluetooth modules have it. Most bluetooth units (the chip itself) are usually 3.3v devices, however some bluetooth breakout boards include level shifting circuitry and can thus, be operated at 5v.
Double check the comments above on the same topic and check your datasheets.