VMAC PiHat v1 to v2 Changes
VMAC PiHat V2 is a compliment to the original V1 board. v2.4 is the current version.
At a glance changes:
- On Screen Display Graphics With Matrix Switching
- Video Signal Detectors on Three Video Inputs
- Separate Pi Audio Matrix Inputs
- Dedicated 3V3 Regulator
- Removed 5V DC Input Regulator
- Improved Matrix/OSD matching
- Remove Input Diodes
- Increased Test Points
- EEPROM Addressable from User Programs and Scripts
- Additional User LED
PCB v2.4 Full details here
The principle changes between V1.1 to V2.0 and V2.4 are listed below:
- Increased RCA dedicated inputs to 6 x Audio or Video
- Separated Pi Audio L/R Loopback from Input 5/6. They now go to separate Matrix Inputs for increased flexibility
- Included new OSD Graphics with fully selectable Matrix switch control to allow OSD only or OSD with Video (any input)
- Included new on-board automatic video detectors (for receivers with no squelch or CCTV / FPV camera use)
- Removed 5v regulator due to heat dissipation from LDO and importantly gives back room on board for OSD as did not want to populate two sides
- Changed PiHat 3v3. No longer taken from Pi 3v3 on header. Now uses new dedicated 3v3 regulator. This reduces current and increases flexibility for other CPU boards/types.
- LEDs now in a row, just to make it clearer
- Input diodes pad size increased slightly to make user hand soldering easier
- DTMF input solder pad jumper to easily select preference from Matrix Out 8, static Input 6 or JST Header
- Remove Input Diodes (v2.4)
- Added rear solder jumper to enable EEPROM to be used on the PI, or on the I2C bus for general use. (v2.4)
v2.0 to v2.4
- OSD CS
- OSD RST
- EEPROM Solder pads
- TP OSD LOS
- OSD to Matrix matching – add R/C
- Move solder pads to underside
- Add Input 2 and Input 4 PCB pads for test and development use
- OSD input and output matching and level updates
- Video Detect LOS Level shifter on each output
- Add additional test points
- Remove input protection diodes
- Add additional User LED on RTS GPIO 17
PCB v2.0 Developer Edition
PCB v2.3 Internal Testing
GPIO Changes (Existing software will work apart from tweaking DTMF D1 – new test code will be provided)
- Moved DTMF D1 from GPIO 10 to GPIO 19 (To clear SPI bus for MAX7456)
- GPIO SPI now goes to the OSD MAX7456
- The unused GPIO 18, 23 and 24 are now used for the Video Detector Auto Signal Sensing VD_1, VD_2 and VD_3
- OSD RST Enable/Disable on GPIO25
Components
- Add 1 x 3v3 Regulator (MCP1703 Low Quiescent Current LDO Regulator)
- Add 3 x Auto Video Input Detectors (MAX7461)
- Add 1 x OSD (MAX7456)
- Add 1 x 3v3 Power LED
- Add 1 x SPI level shifter for MAX7456
- Remove 5v Regulator and DC Input Jack
- Remove Set of Input Diodes (v2.4)
- Update Passive Matching Components between Matrix and OSD (v2.4)
Updated PiHat V2.0 and v2.4 schematics can be found here