Jump to content
Arthur P.

Programming adapter for ATMega8 SMD chips

Recommended Posts

Not sure whether there is a thread here already on a programming adapter for surface mounted ATMega8 chips. Within the http://www.mikrokopter.de/ forum under Brushless Controlers, converting brushless controlers to I2C (Umbau von...) there is a bit of discussion ongoing about making adapters which allow the ATMega8 chips on cheap brushless controlers such as the TowerPro 25A ESCs to be reprogrammed without having to solder thin wires to the MISO, MOSI, SCK, and RST pins. I had already thought about using very thin latex as flexible membrane and epoxy for the adapter. Problem with that approach is that without casing and even with just 5min curing time you can't get enough pressure on the stuff to get a good imprint of the processor. Today at a creative hobbies shop I found a new type of plastic clay which just needs 10 min in the microwave to harden instead of the 30 minutes of stinking up a kitchen with the old plastic clay stuff. And this new material ways near to nothing, showing promise for e.g. complex curves in RC models.

Gave it a very quick and dirty try this evening, using a 1 cm3 piece in a somewhat elongated form so that it could be pulled off the processor without deforming the base. After 5min in the microwave it is still soft enough to cut with a knife into a nice square adapter with a flat top, but hard enough not to deform. And even with this QAD try I think the imprint is already so accurate that drilling from the inside out from the required pins would allow accurate positioning of the progbramming wires over the correct pins. A simple small clamp can hold this adapter firmly in place. Would probably cut about 30-60minutes off of the conversion process and require only the SCL and SDA wires to still be soldered onto the processor pins, and 1 additional wire for rerouting of an ADC line.

I-ve posted pics here at the end of the TowerPro 25A ESC PWM to TWI/I2C conversion thread: http://www.rcgroups.com/forums/showthread....t=766589&page=3

Share this post


Link to post
Share on other sites
This is what I made for Atmega 28 DIP to 32 MLF:

1744599746_28ea497e71.jpg

Isn't this an adapter for not yet mounted ATMega8's? What I-m proposing is an adapter that can be used for chips which are already soldered in place, e.g. for reprogramming ESCs.

Share this post


Link to post
Share on other sites
Isn't this an adapter for not yet mounted ATMega8's? What I-m proposing is an adapter that can be used for chips which are already soldered in place, e.g. for reprogramming ESCs.

This is an adapter for programming not yet mounted and mounted (soldered) Atmega8's. I have developed this for the Arduino environment... it is testing now...

When used with the Arduino environment, it can be programmed through USB (Atmega needs to have a pre-programmed bootloader) or you can burn hex files through ICSP.

Share this post


Link to post
Share on other sites

Well after some experimenting I managed to create a programming adapter for less than 1 USD in material costs B)

Material used: plastic clay (that coloured stuff that children clay with) which gets hard when baked for 30 min at 125C in the kitchen oven, and a few strands of wire-wrap wire. Only tools needed: very thin drill-bit (a fraction thicker than the wire-wrap wire with insulation), a sharp knife, the kitchen oven, and finally the trusted soldering iron to connect the adapter to thicker wires and your favourite programming plug.

I-ve posted more details and pics here: http://www.rcgroups.com/forums/showthread....e=9#post9123848

post-2251-1202847324_thumb.jpg

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×