Hardware: MinimOSD rev.0.1 board from http://www.goodluckbuy.com/on-screen-display-osd-board-minimosd-apm-telemetry-to-apm-1-and-apm-2.html
Total cost: u$s 21
I have to say that the idea of an OSD MAVlink 1.0 sounds great, but I only have a couple of MinimOSDv0.1 and DIYdrones offers MinimOSD rev1.1. from u$s 62.
I don’t quite know which is the difference between them. I saw that the main components are the same:
- ATmega328P with Arduino bootloader
- MAX7456 monochrome on-screen display
Bootloader? wtf? Well it’s a small peace of code which is executed at the beginning for couple of seconds and then it runs the default sketch.
Well I didn’t know if Minim rev.0.1 had a bootloader in, actually a didn’t know that such a thing exists. So I will suppose that bootloader is already loaded in Atmega328p, and just in case I will explain to you how I did to burn a bootloader in.
Updating MinimOSD rev. 0.1
First you have to use a serial adapter to connect MinimOSD to PC. I did use a FTDI adapter from Rctimer.
From http://code.google.com/p/arducam-osd/ download two files:
Unzip Config OSD and execute OSD_Config.exe then go to Options –> Update Firmware and select file MinimOSD2.0.hex, once you have picked it ConfigOSD will try to connect to bootloader, but at this point bootloader is not running so the easy way is to press reset button at the same time then bootloader will answer the request. I you miss an error message will show up indicating that bootloader couldn’t be found.
At my first attempt I didn’t know that so I thought that bootloader was missing. So I burned again. But this is another how to.
In order to test your settings please use a MAVlink1.0 tlog file from APM Mission Planner. Usually found at C:\Program Files (x86)\APM Planner\logs. Go to Options –> Sent TLog.
Connect MinimOSD to CRIUS AIO PRO v1.0
I did connect the OSD to Arduino Serial3 a.k.a. S3 (Tx3 and Rx3) in CRIUS boards. This pins are perfectly labeled.
Then you have to add a couple of lines to APM_Config.h in order to activate MAVlink1.0 Telemetry port over Serial3.
#define GCS_PROTOCOL GCS_PROTOCOL_MAVLINK
#define GCS_PORT 3
#define MAV_SYSTEM_ID 1