Features: 1. Based on the for raspberry pie 40PIN design, it can be inserted directly. Lead out all GPIO function pins and test whether all pins function normally. 2. As a test board, test whether all pins of for raspberry pie 3B/4B/CM4 are intact. As an expansion board, this module includes LED and basic functions, which you can use easily. 3. This is a simple expansion board, suitable for beginners of raspberry pie. For raspberry pie 3B/4B hole position, can also work in zero. 4. With demo code and user guide, easy to use. The onboard ADC chip can read the ADC signal as the sensor expansion board and send the DAC signal. 5. On-board industrial wiring terminal female port, terminal with interface definition sticker, more beautiful and practical. Specifications: Product name: PCF8591 sensor LED expansion board Model: Pi ALL GPIO TEST BOAR Type: LED test board Size: 6.5cm x 5.5cm x 2cm Material: PCB+Metal colour: Blue Package Contents: 1 x Pi ALL GPIO TEST BOARD(B) 1 x Screw package Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.