Micro controllers needed for professional PCB

Hey, I have been part of a funding programme and I need to develop a wearable band as a part of my project. I have made a breadboard prototype, now it's my time to make a miniaturized version of it. Obviously, PCB's are the way, but the thing is my team are still in the stage of developing the prototype.

In order to do this, we need to frequently burn the code into the microcontroller, but it is very hard and a bad idea to constantly pick the MCU out of the board, programme it and resolder it again. And I cannot even accept to have a USB connector and onboard debugger in order to establish a hardware programmer. So please do suggest me a way which microcontrollers are easy and efficient to programme and interface with my PCB. I am planning to use an ATMega microcontrollers, I feel they are the best. I know you can prove me wrong, please suggest me ways.

you can email me here testuers234@gmail.com

If you leave the bootloader in your ATmega chip, you only need 3 wires (RX, TX, reset) to connect to an "uploader" to load new code - that's all that the Arduino have in between the USB chip and the AVR.

With one of the new UPDI AVRs, it would only need the one UPDI pin.

(in addition to ground...)

Put square pads on your PCB and use a test jig with pogo pins to program it.

You can then program this with the serial interface or the program header on most Arduinos.

Hey Grumpy_Mike,

How about using a 8 pin SOP programming socket kind of thing? I will be using an attiny85 SMD package MCU for my applications as of now, so is it a good idea to programme it like that? Or any new methods that i can follow

They are a bit big for a prototype as are ZIF sockets which is why I didn’t suggest them.

Fine for programming but you still have to repeatedly insert it in the board’s socket.

Depending on what you do with certain pins, you can also put an ICSP interface on your board, and use a programmer to bypass the bootloader.

Hey Chris,

Please help me more on it, ICSP is the exact thing I've been thinking off too.

You will need a "programmer" or hook up a spare Uno to act as a programmer. Then you can send a program to most avr chips by using the reset, mosi, miso and sclk pins without removing the chip from the circuit.

Here is Arduino's tutorial: https://www.arduino.cc/en/Tutorial/ArduinoISP