The Loongson LSIC300A robot controller user manual explains hardware connections, PWM expansion, and software setup via TF‑card.
The manual describes how to power the LSIC300A controller using its two USB ports (mini‑USB works) and connect the required cables, including three servo leads and an external 7.2 V supply for the servos. Two PCA9685PW chips expand the controller to provide 32 PWM channels (up to 16 per chip).\n\nSoftware setup is performed by copying the kernel and file‑system images to a TF card, inserting it into the board, and using U‑Boot commands to load the kernel, root file system, and set boot arguments. After boot, PWM channels appear as pwmchip0 and pwmchip17, and their period (20 ms) and high‑level duration (e.g., 1.5 ms) can be configured to drive servos such as the DS3115mg. This manual is written in Chinese.
| PWM channels | 32 channels (two PCA9685PW chips, 16 per chip) |
|---|---|
| Servo supply voltage | 7.2 V external |
| PWM period | 20 ms |
| PWM high‑level duration (example) | 1.5 ms |
| Supported demo servo | DS3115mg |
It provides 32 PWM outputs using two PCA9685PW expansion chips, each supporting up to 16 channels.
Copy the kernel and file‑system files to a TF card, insert the card into the board, and use U‑Boot commands such as `nand erase.part`, `fatload`, and `nand write` to flash them.
Set the PWM channel period to 20 ms and adjust the high‑level time (e.g., 1.5 ms) to control servo position.