On Kickstarter: Sequent has launched a $50 “Raspberry Pi I/O Learning Kit” with an STM MCU, 4x opto-isolated inputs, 2x relays, RS485, PWM output, power I/Os, and a Node-RED learning tutorial.
Sequent Microsystems, which specializes in Raspberry Pi add-on boards for I/O controls, such as its 16-Inputs for Raspberry Pi HAT, has now spun another Pi add-on aimed at teaching embedded I/O concepts using Node-RED, complete with downloadable tutorials. The company has already won Kickstarter funding for the $50 Raspberry Pi I/O Learning Kit, which ships in January.
Raspberry Pi I/O Learning Kit with (left) and without the Raspberry Pi
(click images to enlarge)
The Raspberry Pi I/O Learning Kit is equipped with a 32-bit STM microcontroller, an RS485 serial port transceiver, and a PWM output capable of driving a 5VDC/100mA motor. Other features include 4x optically isolated contact closure inputs and 2x relays that can drive 8A and 24V loads with LED status. You also get a 0-10V input and output and a 4-20mA current loop input and output, a pushbutton, and 4x programmable LEDs.
The I/O board is powered by a BYO Raspberry Pi via GPIO. It requires 5V/50mA to operate with the relays off or 200mA with both relays on. The kit includes 2x 2-pin plugs for the RS485 and PWM-driven micromotor, 8x 3-pin plugs for the I/Os, a self-test loopback cable, and brass standoffs, screws, and nuts.
Raspberry Pi I/O Learning Kit block diagram (left) and detail view
(click images to enlarge)
The KS page mentions an optional add-on kit that is not included among the standard packages. You can add the $25 kit at the end of your pledge. The kit supplies an on/off switch, thermistor, photoresistor, potentiometer, RS485 temperature and humidity sensor, and a micromotor.
Sequent has already posted a link to the first three chapters of the 12-chapter Node-RED tutorial. The tutorials show how to use the Node-RED visual I/O programming environment to control each of the interfaces of the Learning Kit. Examples range from building simple flows using the pushbuttons and LEDs to controlling devices over the Internet.
We asked Sequent Microsystems founder Mihai Beffa if the recent flurry of product announcements after a major slowdown over the summer meant we might be coming to the end of the chip shortage. “All signs are that the end of the shortage is nowhere near in sight,” answered Beffa, noting that a simple TI TCA9535PWR I/O expander that sold for $0.50 earlier this year now sells for $5. However, Sequent has already secured the chips it needs for at least 1,000 units.
The Raspberry Pi I/O Learning Kit is available on Kickstarter through Nov. 26 for $50, with volume discounts. Shipments are expected in January. More information may be found on the Kickstarter page, and more should eventually appear on the Sequent Microsystems website.