It’s been a while since the last post… mostly because my new job is taking away most of my time…
But also because I had to fix several issues in Anima before mounting the legs and the upper body. First I had to fix the sound problem, curiously the IR sensor was generating noise which was propagated up to the audio amplifier, thus generating audible noise… To fix it I added to capacitors (100nF & 10µF) on the sensor’s power connection. Then I burned the Li-ion charger 😦 so I had to replace some mosfet and add some heatsinks.
Finally after 20 months of design, tests, doubts, bug fix, etc… Animabot is assembled and ready to walk !!!
Stay tuned 😉
Hello ! The assembly of Animabot is going well, I have almost finished 🙂 I’m mostly making cables and cables… Thinking about how I’m gonna put all of them into the body… But anyway, I’m also testing the electronic and everything is also fine up to now: Audio amp and speakers, IR telemeter, fan, Night LED, temperature sensor and power monitor and the ATX Raspi are working !!!
The Rapsi is also much thinner without all these big connectors 🙂 but I have some issues with the WIFI dongle and I need to test the webcam.
So I put all the parts together to see if all goes well, and for now it’s look like this :
Power ON baby !
I like it ! even if the parts are not perfect as I would like, and even if the design is full of errors, it doesn’t look so bad 🙂
More update soon 😉
First video of Animabot ! well it’s not the robot yet, only a bunch of electronic boards and 2 servos, but it’s something 🙂 The servos move accordingly to the STm32F4 tilt.
Hey, It’s been a long time since I posted news on Animabot 😉 I didn’t advanced much on the software but I can now talk to the servos which is a very good news 🙂 I still have to make all the functions to control them correctly (setPosition, getPosition, moveAll, setTorque, getTemp, etc.) but it will be more interesting !
I’m still waiting for my 3D printer… and it begins to annoy me…
Servos are alive !
Servos are alive !
STM32F4 under programming
A small update about the boards, as you can see on the photo below, the boards are connected together and the power is well-distributed in each of them.
I have also set up my software environment using Eclipse and ChibiOS RTOS. I can now working on the STM32 configuration and mid-level implementation for ADC, SPI, LTC2945, Sensors (Temp, IR, accelerometer) etc… The Serial Driver is already working so I can at least use printf for debugging 🙂
As I’m still waiting for my 3D printer, So I concentrate of the software and I will continue the mechanic later.
I finally received my samples from Texas Instrument for the voltage regulation. I chose to use several switching regulators in order to clearly separate each feature.
- The little one on the top left is a PTN04050C, it will be used as 5v power supply of the RasPi, the STM32 and the class D ampli of the speaker.
- The two on the left are PTN78060WAH, I will used only one for the light LED for night vision.
- The tree on the right are PTN78020WAH , they will be used the the legs: One for 2 legs (front, middle, rear).
Modules characteristics :
- 3-A Output Current (PTN04050C and PTN78060W)
- 6-A Output Current (PTN78020WAH)
- Wide-Input Voltage (2.95 V to 5.5 V) : PTN04050C
- Wide-Input Voltage (7 V to 36 V) : PTN78060W and PTN78020WAH
- Wide-Output Voltage Adjust (5 V to 15 V) : PTN04050C
- Wide-Output Voltage Adjust (2.5 V to 12.6 V) : PTN78060W and PTN78020WAH
- High Efficiency (Up to 96%)
- On/Off Inhibit
- Under-Voltage Lockout
- Output Current Limit
- Over-temperature Shutdown
- Operating Temperature: -40°C to 85°C
Animabot will use 2 batteries :
- 3.7v, 2500mAh Li-Po with charger for the brain
- 7.4v, 3900mAh Ni-MH for the legs
Each battery will have its own charger integrated in the robot, with one input connector for both.
The charger of the 7.4v battery is a LTC40008 , but it is only the chip, so I will have to make the circuit on the mother board. I will see that later…
The two batteries will be monitored by a specific component : LTC2945 (one one each). Animabot will be able to check the voltage and current on each battery and when the batteries will be low, Animabot will put itself on power saving mode, or sleep mode.
For the moment I am using another DC-DC boost converter from dfrobot for testing purpose, but in the future I will replace it by the PTN04050C on the motherboard.
Brain Power Supply
Brain Power Supply
The Raspberry Pi is flashed with the Raspbian OS (quick start guide available here).
The STM32 is flashed with the RTOS ChibiOS. ChibiOS is compact, fast and open source OS : Perfect for me !
STM32F4 Discovery Board
I modified the power connector of the Pi in order to connect it with another connector. As you can see on the architecture document, I will use a small 3.7v Li-Po battery for the Pi and the STM32 with a special power supply (PTN04050C). So I soldered a JST connector with cables :
Brain Power Supply
The Raspberry Pi will will equipped with a “smart switch”. As you are running a Linux on it and a SD-Card, you can not unplug the Pi as you wish. If you shut off your Pi while it is writing on the SD-Card, you might corrupt this one… And you will have to flash it again… 😦
So to prevent this a found what I call a “smart switch” from Mausberry Circuits :
With this switch, you only have to install a small script on the Pi, and that’s it 😉 You can now power ON/OFF your Pi safely !
Concerning the STM32, I can directly use the 5v pin, so i don’t need do modify the board. The STM32 can be shut-down directly without special precaution, so no problem as for the Pi.