These are my nodes on the Shari SA818 module in the context of All Star Link. I hear a lot of negative comments about the quality of this device. Or, to be fair, the quality of the imitations being sold on the internet. But there are many ASL stations based on some variation of the Shari board so it’s important to have good integration for Ampersand.

Please see my SA818 page for information about the radio module itself.

Heres a schematic for one variation of this device.

The board contains a CM108 for audio input/output.

CM108 input signals:

  • The SA818 SQ signal is connected to the CM108 VOLDN pin. This is consistent with the usual convention: COS -> VOLDN.

CM108 output signals:

  • The SA818 PTT signal is connected to the CM108 GPIO3. This pin is mapped to HID_OR1 in the 0b00000100 bit position. This can only be written when HID_OR0 0b11000000 is set to 0. For reasons that aren’t clear to me (and not consistent with the datasheet), turning on GPI03 requires a 5-byte write { 0, 0, 0x4, 0x4, 0 } and turning it off requires a 5-bute write { 0, 0, 0x04, 0x00, 0 }. The first 0x04 is tbe mask that sets GPI03 as output and the second 0x4 is the “high” signal or the “low” signal.