Ravinder Singh's Plug-and-Play USB-TTL Boards Offer Three Different USB Connection Options in One
With full-size USB Type-A male, micro-USB, and USB Type-C connectivity on every board, these USB-TTL adapters pack in the features.
Embedded engineer Ravinder Singh has put together what he describes as a "complete plug-and-play USB-UART interface solution" hardware family, built around the WCH Electronics CH340 or Silicon Labs CP2102 chips and boasting three different USB ports per board — and it's called, simply enough, the USB-TTL.
"USB TTL is developed with the advanced CP2102 and CH340 chipsets, which are [USB] 2.0 compliant and come with standard USB Type-A male, Type-C, micro-USB, and TTL 6-pin connectors," Singh writes of the hardware. "3.3V, VCC, RTS, TXD, RXD, GND, CTS, and 5V are all represented by six pins."
The low-cost adapters are designed to connect transistor-transistor logic (TTL) level serial ports on embedded hardware to a development system via USB. As with rival designs, the USB-TTL range features a 2.54mm header to one end for connectivity to the target system and a full-size USB Type-A connector to the other for the host — but then distances itself from its rivals with the inclusion of micro-USB and USB Type-C ports to either side, offering three different host connectivity options in total.
Other features include a jumper for selecting between 3.3V and 5V TTL devices and support for data transfer rates from 50 bits per second (bps) all the way up to 6Mbps. On both devices, all six UART signals are broken out: transmit, receive, request-to-send (RTS), clear-to-send (CTS), transmit, receive, 3.3/5V, and ground. Status LEDs are also provided for power, receive, and transmit.
Pricing for the parts varies depending on which USB UART chip you choose: Crowdfunding pricing for the USB-TTL CH340 has been set at £3 from a planned £4 retail price (around $3.85 and $5.15 respectively), with the CP2102 version costing £5 from a planned £6 retail (around $6.40 and $7.70 respectively). A combo pack offering both chips is also available, along with five-packs of each.
The USB UART adapters, produced by SB Components, is now funding on Kickstarter with hardware delivery expected to take place in July this year.
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