Descriptors
Posted: Sat Jan 29, 2011 1:27 pm
Hi all.
Im having trouble setting up my descriptor for my ATmega88, as it seems that windows wont regonize the software i flash onto my chip.
Background:
Me and a mate have been fooling around with the ATmega88 for a while, and we are pretty much into registers, interrupts, adc etc. on this chip. It have been quite fun to play with it and then we decided to make a temperature gauge which we want to hook up with a PC and collect the data. The thing is that we have designed at circuit which will give an output to the PC0 connector on the chip, which will be converted in ADC and put in ADC data register (10-bit resolution), the plan is that we wanna send these raw data to the pc and let it do the work.
The Problem:
The problem is writing a descriptor that will be regonized by windows (probably other OS'es aswell). I have read USB in a Nutshell, been looking in HID Usage Table, read USnoobie's tourial on this matter, which btw was the most given compared to the Nutshell document. But it still seems i cant crasp the concept, i have been using a few days on this matter, looked in this forum and other sites on the internet. And now im like, I'll have to ask someone with expirience in this matter.
The data structure is quite simple as we wanna send the raw data from the ADC data register to the PC, so im thinking it would look like this:
Furthermore i found that the device we wanna make is PID (Physical Interface Device) and the INPUT is Data, Variable, Absolute. Im not sure if i have to use logical min/max, but i would like to as its simple 0 - 255. I have tried using the HID Descriptor Tool, but this a jungle to make my own descriptors, I'm feeling kinda lost with this and I/we would appreciate some help if its possible to help with this matter.
Greetings
- Kent
Im having trouble setting up my descriptor for my ATmega88, as it seems that windows wont regonize the software i flash onto my chip.
Background:
Me and a mate have been fooling around with the ATmega88 for a while, and we are pretty much into registers, interrupts, adc etc. on this chip. It have been quite fun to play with it and then we decided to make a temperature gauge which we want to hook up with a PC and collect the data. The thing is that we have designed at circuit which will give an output to the PC0 connector on the chip, which will be converted in ADC and put in ADC data register (10-bit resolution), the plan is that we wanna send these raw data to the pc and let it do the work.
The Problem:
The problem is writing a descriptor that will be regonized by windows (probably other OS'es aswell). I have read USB in a Nutshell, been looking in HID Usage Table, read USnoobie's tourial on this matter, which btw was the most given compared to the Nutshell document. But it still seems i cant crasp the concept, i have been using a few days on this matter, looked in this forum and other sites on the internet. And now im like, I'll have to ask someone with expirience in this matter.
The data structure is quite simple as we wanna send the raw data from the ADC data register to the PC, so im thinking it would look like this:
Code: Select all
typedef struct
{
uchar adc_upper; // 8-bit data
uchar adc_lower; // 8-bit data
} report_data;
Furthermore i found that the device we wanna make is PID (Physical Interface Device) and the INPUT is Data, Variable, Absolute. Im not sure if i have to use logical min/max, but i would like to as its simple 0 - 255. I have tried using the HID Descriptor Tool, but this a jungle to make my own descriptors, I'm feeling kinda lost with this and I/we would appreciate some help if its possible to help with this matter.
Greetings
- Kent
