I’ve started to receive the components I need for my 2WD obstacle-avoiding robot.
I got the motor shield which is a clone of the Adafruit one it seems, however its quite poorly made – the silkscreen that says which servo is which is backwards, one of the L293D chips wasn’t sitting straight in its socket, the high voltage terminal blocks for the motors are dangerously close to shorting on the Uno’s ICSP pins and USB socket (I fixed with some insulating tape) and the reset button is soldered at a bit of an angle! It does at least fit on the Uno SMD clone, I wasn’t sure it would due to all the extra pins they’ve added to the Uno.
I tried out both motors and servo’s using the shield and it worked. I found that its pushing it a bit to run both servo’s at once as they use the power from the Uno, not the external power, however I’m only using one, and I could get two to work if you don’t overwork them – like spinning from 0-180 in 15ms steps!
The motors work well, they certainly go faster with 6v applied to the ext_pwr terminals than 4.8v that 4xAA’s would give me, so I’m really considering that 7.4v LiPo now.
I found that the mini variable DC/DC converters I’ve got actually switch to a boost converter when the voltage drops to about 1v above what you want, so that’s not much use, but the micro models stay at the voltage they’re set to, so won’t suddenly go to 6v when you’re trying to get 5v from a discharging 7.4v LiPo!
My Salea clone logic analyser arrived and I can’t believe how small it is – about 1×5.5×2.5, smaller than a 9v PP3 battery! It works just fine with the new Logic v1.20 beta software and Sigrok’s Pulseview software. In some ways I prefer Pulseview as it has more decoders and a proper GTK+3 theme. I’ve not had much success with sniffing SPI/I2C off an ESP8266/nRF24L01+/DS1307 yet, but certainly got the duty cycle etc. from an Arduino running Blink just fine. I really need those test hooks!