Everybody likes rapid development kit. These boards should be easy to interconnect to a number of boards/shields and offer firmware to jump-start to start testing the idea.
What better to have click modules designed by Mikro-electronica which offers more than 500+ boards to connect any type of peripheral.
esp32 from express-if is another popular board that offers wifi/Bluetooth along with a number of peripherals bus to connect to a variety of devices.
Combining these two functions on the board boosts a number of different ideas that can be implemented with this board.
So introducing our new board named esp32 rapid development click board. The board has been designed using Circuit tree app autonomously except for some placement change and silkscreen updates which were done manually.
Here are some of the key features of the board:
ESP32D-WROOM Module used.
USB/Battery powered board
On-Board UART to USB function for debugging and programming.
Onboard regulators of 3.3v/5V along with control logic
Switch and LED’s to provide status.
Here are some of the screenshots of the top/bottom SVG renderings.
esp32 rapid development board-PCB Fabrication -Top side
There is much more planned fun along with the board which would be shared in upcoming blogs.
This board is available on sale from our website.
Designing a board gives a lot of satisfaction and fills you with motivation to keep going. The happiness and motivation that we got from the project were boosted much more as it was not only the successful board bring up but it was the Circuit Tree application that was also tested.
We are big fan of Python as it is extensively been used on most of our development tasks. One of our colleagues mentioned to create a third board using circuit tree having micro-python running on it. That sounded like a cool idea.
We wanted to build the board having feature set similar to the micro python 1.1 board. The additional constraint was to even have the interfaces and the dimensions the same.
Using Circuit Tree the design was loaded using command line entry through schematic. The Circuit Tree application autonomously completed these different activities:
Interconnected the components specified in the requirement.
Selected power, clock, reset components
Selected discrete values needed by different components as per the electrical requirement.
Generated the clean and error free schematic
Accepted the board boundary which was the micro python form factor.
Completed board placement. This placement had to be modified as some some components were placed far off. So human intervention was done here.
Generated a two layer PCB design on it own. All the pcb routing, plane creation, Thick traces routing , length matching was autonomously. Here Human intervention was introduced to redo some traces. Human intervention was introduced to ensure that the design was correct.
Gerber files were generated by the app after the silk screen was updated by engineer working on the program.
Using BOM component links the components were ordered. So yes it was minimal human intervention and feels good looking at the task circuit tree application is now able to undertake.
It is a two layer design with pictures below displaying svg of all layers, bottom and top layers.
Bottom side pyboard1.1
Top side pyboard1.1
And here is the PCB Fabricated using circuit tree application design:
The board is now under pcb assembly. Waiting patiently to get the boards so that we can load the micro python the board.
The PCB has been in India and this is the third board from us. Lots of learnings along the way.
We dream for the day when we are able to design complex boards (6+ layers, 400+ components including BGA components) using Circuit Tree application under 3 hours of effort.
If board design is a pain point for you write back to us what you would like us to solve.
We have chartered a new goal to create development boards of the designs created by circuit tree to showcase Circuit Tree Design capability. To keep the task fairly simple the development board requirements are listed below:
1. Create a drone board which can fly while being controlled from mobile bluetooth. The frame of the board would be a PCB where the Motors would mount.
2. The drone board should be powered by a battery and should have battery charging capability.
3. The Main elements of the drone board would be a small micro-controller, bluetooth radio, accelerometer, gyroscope, compass, jtag port for debug, 4 pwm’s, led and reset switch.
4. The battery of this board when in air should last for minimum 15 minutes.
5. As a first bringup goal the drone board should be able to fly till small altitude.
Next we start the electronic design. We chose circuit tree design to first look at the list of controllers which can be used for the drone design. Based on the component avaibility results we narrowed down to stm32l052k6t6 from st micro electronics. Quickly the components were selected as shown below and a block diagram generated.
Board requirement capture screen
Board block diagram of the components selected
We did wait for schematics to generate within 2.5 minutes and within that time did scan the Bill of material file generated from the tool. There are certain discrete components which circuit Tree could not select which is left to the designers to update.
Also in the schematic we have a dummy connector added for Timer pins. The connector is important as it helps in allocating the micro-controller pins for the Timer/PWM. The intent of using Timer is to allow mosfets to be added to these pins to eventually allow motors to be driven.
Next we click on the layout viewer to select a dxf file and check if the placement dxf outline is correct. Next we fire the background process to generate placement.
Board components prior to start of auto placement algorithm
Within next 3 minutes the placement of the board is generated and it looks as shown below:
Finished Board component placement
The algorithm shows that the components can be fit in the given board dxf file. It is time to define the board boundary restriction so that the algorithm can rerun and produce more symmetrical placement around 4 weeks.
We would keep updating the blog as we get the results.
Here is the Git hub link for design files for the drone design.
Update1: Sept 16th 2017
Muneeb started working on the eagle downloaded design to add motors pads and mosfets to the design. He is one of smart engineers we have on circuit tree who took the design and first started to review the design and compare the output of circuit tree with the stm-cube tool output. Once we was happy with the output it was time to change the connector page to add the motors pads and mosfets as shown below. The only change he had to do in the downloaded eagle schematic file was to change the grid to default.
Here is the copy of the page he edited:
Updating dummy connector page with motors pads and mosfet.
The next check for him was to check if the eagle ERC was displaying any errors. No errors were found but number of warnings were observed stating two similar named nets are connected to one another. After a check it was time to see if the the circuit tree board file can get newly added components(mosfets and motor pads) in the placement. He further customised the placement file to meet his requirement.
Board revised placement
Update2: Oct 10th 2017
We have released the board file for fabrication and assembly. Eagerly waiting for the first circuit tree design to come to life.
Stay tuned to know how we progress ahead with this design. We cannot control our excitement.
Update no 3: Oct 20th 2017:
We just got the pcb fabricated from china. There is a minor issue with respect to the via tenting which the pcb vendor did not make despite being in the requirement. Components have been ordered and now the pcb assembly starts.
Top Side of the drone PCB
Bottom Side of the PCB
Looking for a healthy board bringup without any wires.
Update no 4: Oct 30th 2017:
Here are the set of assembled boards designed through circuit tree. Board bringup’s are always interesting milestone for a hardware design engineer as we spark new life into a element.
Quick checks done so far:
Component placement checked
Power short check shows no issue so far.
Weight of the board.
Note there are no overlapping components.
So far so good. It is late in the evening will do the bringup tomorrow with a detailed test plan.
Assembled Drone Boards designed by circuit tree
Update no 5: Nov 2nd 2017
Picture of the board assembled with motors and power test. Board was first tested for open short test. The board was powered with usb cable and then the main board voltage was found to be 3.29v. Great work so far.
Update no 6: Nov 4th 2017
The moment we have been all waiting for is here. Here is a quick update on the board bringup:
Powered the board through the usb cable connected to a laptop. All voltages are good.
Connected the st micro to ST-LINK/V2 through a custom adapter cable as the connector on the board was incompatible with the pitch of the programmer.
Detected the stm32l052 device on the programmer console.
Programmed a code to drive the motors through the mosfet.
Next connected the battery on the board after switching on the board.
Result is as shown in the video. The right side of the drone had more lift compared to left side.
Really happy and satisfied with the result.
The next steps would be to connect the board through bluetooth to power on and off the board using laptop bluetooth control. Also we would interface with all the board sensors to get the real time data.
The good news is that the most of the hardware functionality is working as expected. Circuit tree application has designed a board which is reliable in short span of design time. In hardware design lots of items have to tick right and circuit tree has just shown the capability.
The next update would be in few weeks when we have created the software.
Update no 7: Dec 10th 2017
Here is another update to the drone testing. In the video below you will notice that Bluetooth and a application layer is running on the drone which allows turn on and off of the left side and right side motors. You will also notice that we had to connect a wire on the board to connect the stmicro with the bluetooth transceiver. This wire was added to allow the software to reset the transceiver as needed. This is the option which would integrate in the application.
This is a good learning we have had. In the next update we would share the application software used for the development which would be free to use.