Arduino electronics
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Tyler Folsom
Jun 6, 2014, 3:30:20 PM6/6/14
to Jim Kindsvater, Elcano
Jim -
Checking in. Have you had a chance to look at the MegaShieldDB?
I'm thinking that it is time to come up with new designs for all three circuit boards. I've talked with the department chairman. The lab is going to be expanding. and he wants to buy 8 more lab kits by the end of the year. Each kit consists of Arduinos, shields, and custom circuit boards. The cost of replacing all existing boards in the present 8 kits does not add much to the cost of new kits. Future boards would be stuffed and soldered by the house that fabricates them.
When I had designed the original boards, I skipped the step of breadboarding and testing the electronics. That was a mistake. There are several issues with our existing boards:
MegaShieldDB: Replace the DB9 connectors with something simpler that connects to an RC controller. This interface would not require rewiring the actuator adapters. Remote E-stop does not work as designed.
Sonar mount: The chaining and analog output do not appear to work as documented. May need to switch to PWM output.
MegaShieldTrio: My original design assumed that an Arduino analogRead() could read an analogWrite(); not true. I am also seeing issues with the Arduino Nano. It appears to be something of a step child, with the drivers not as well supported as other Arduino products. There are issues with programming or attaching a serial monitor to a Nano while it is in the Trio board. The loaded MegaShieldTrio draws about 160 mA, too much for some USB interfaces. The Nano cannot be isolated from the rest of the Trio board, since the Rx line brings power to the Nano, and disables the USB. The Rx line is used for communication with another Arduino.
Present design is based on Arduino Mega and Nano. There are other newer parts that we should investigate. Let me know your ideas.
- Tyler
Checking in. Have you had a chance to look at the MegaShieldDB?
I'm thinking that it is time to come up with new designs for all three circuit boards. I've talked with the department chairman. The lab is going to be expanding. and he wants to buy 8 more lab kits by the end of the year. Each kit consists of Arduinos, shields, and custom circuit boards. The cost of replacing all existing boards in the present 8 kits does not add much to the cost of new kits. Future boards would be stuffed and soldered by the house that fabricates them.
When I had designed the original boards, I skipped the step of breadboarding and testing the electronics. That was a mistake. There are several issues with our existing boards:
MegaShieldDB: Replace the DB9 connectors with something simpler that connects to an RC controller. This interface would not require rewiring the actuator adapters. Remote E-stop does not work as designed.
Sonar mount: The chaining and analog output do not appear to work as documented. May need to switch to PWM output.
MegaShieldTrio: My original design assumed that an Arduino analogRead() could read an analogWrite(); not true. I am also seeing issues with the Arduino Nano. It appears to be something of a step child, with the drivers not as well supported as other Arduino products. There are issues with programming or attaching a serial monitor to a Nano while it is in the Trio board. The loaded MegaShieldTrio draws about 160 mA, too much for some USB interfaces. The Nano cannot be isolated from the rest of the Trio board, since the Rx line brings power to the Nano, and disables the USB. The Rx line is used for communication with another Arduino.
Present design is based on Arduino Mega and Nano. There are other newer parts that we should investigate. Let me know your ideas.
- Tyler
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