Linux started seeing a serious increased usage in embedded projects with raspberry PI due to it’s availability and low cost. And the last years have provided a large number of low cost embedded Linux solutions. They are getting smaller, more powerfully and decreasing in cost making them very attractive in projects. Raspberry PI might still be the king, but it is far from alone these days. Having been involved in a few projects using Linux I must admit that it is very attractive to have a Linux Core as soon as you have Ethernet or Wifi involved.
The module above measure 18x33mm and run Linux. It is no comparison for the larger Raspberry PI or BeagleBone boards, but it cost ca 9.- USD , have a small size and some very interesting features.
This shows a block diagram. The module uses the HLK-7688A SoC and add 128MB Ram and 32Mb Flash in the module. This is supported by Linux/OpenWRT and one of the 19.- USD dev kits is a 5 port LAN/WAN router.
- MCU is MT7688AN ticking at 580Mhz w/128Mb Ram and 32Mb Flash.
- Size 18×32.8z2.8 mm.
- Cost ca 9.- USD
- Wifi with ITX antenna as well as supported on the pins.
- I2S
- I2C
- SPI
- USB
- SD-Card
- JTAG
- 5 x Leds (GPIO)
- 2 x UART
- 5 port Ethernet 10/100Mbps
- + more
The module above is Beaglebone TI AM3352 costing 19.- USD. A little to large to fit on a Hat size, but this one is a serious competition to Raspberry PI. It also have several bigger brothers. The main attraction with the Siera is that it also have PRU’s – co-processors capable of very fast IO.
Moving on I was initially planning a Ethernet module w/ESP32, but are seriously thinking about making a 3 port Router/Hat w/HLK-7688A. I just need to convince myself that the toolchain is available and easy to deal with. I am actually a bit spooked as this involves dealing with a Linux distribution, but lets see.