January 15th, 2011 § § permalink
While I’m debugging ARTv4 to have interesting, pseudo-intelligent behaviors (and not running out of SRAM which causes it to reset randomly…), I’m also working on the next generation electrical design for ART… I’m naming the bundle of software and electronics ARTv5.
The plan is to support more infrared and ultrasonic sensors with an RF transceiver for sending telemetry information. I also want to start producing and using PCB boards to get away from the fragile breadboards.
More specifically, these PCB will take the form of Arduino-shields that I can stack on top of each other.
The plan right now is to create three boards that are stackable:
- One for the ultrasonics sensors (front, rear, left, right);
- One for the infrared sensors (front, rear, left, right);
- One with four connectors to ultrasonics sensors, infrared sensors, motors control in addition to the connector for the RF transceiver.
The last “shield” will also host the CPLD (Xilinx xc9536). All incoming and outgoing signals go through the CPLD to give me the flexibility to do additional processing using digital logic instead of the microcontroller code. In addition, I also have a Texas Instrument CC1101 chipset transceiver (supposedly RFC1100-A but the board they sent me has FT1100A-100) with Power Amplifier that I’m adding so that the Microcontroller can send back telemetry information to the PC…
So there’s the following connections:
- Ultrasonics sensors shield: 10 wires (1 VCC, 1 GND, 4 echos, 4 triggers);
- Infrared sensors shield: 6 wires (1 VCC, 1 GND, 4 signals);
- RF transceiver: plugs into two 9×2 headers (1 VCC, 1 GND and the SPI wires);
- Four control motor wires for the H-bridge (used right now to connect directly to the RF transmitter as a hack).
To do the design, I’m still using the fantastic Fritzing 0.4.3. Although it does crash regularly and has various nitpicks that, if solved, would make this even better there’s nothing really comparable. The workflow feels natural and the results are attractive. I haven’t been able to produce etchable versions of my PCB design due to what seems to be a bug, but the Gerber RS-274X files it generates seem to work fine (if GerberView output is any indication).
I’ve compiled a list bought so far and the cost so far is a bit under 800 RMB. On the basis of that new design I need to add to the wishlist a whole bunch of stackable female headers in addition to figuring out the cost of producing the PCB.
The BoM generated by Fritzing for the ART Shield says:
- 1xGeneric female header – 10 pins;
- 1xGeneric female header – 2 pins;
- 2xGeneric female header – 4 pins;
- 1xGeneric female header – 6 pins.
January 9th, 2011 § § permalink
To get ready for the Robot Contest event on 1/16, I order the RMB 58 RC cars from Taobao. This RC car is good size and properly built. Originally, I wanted to go with the route of replacing the control board with Arduino and drive everything there.
As I was trying to hook up the motor to Arduino, I realized that there wasn’t any H Bridge and it was way too cold to go out and get it. Hmm… I figure there must be some H Bridge on the control board I just rip out of the car.
As I located the two H bridge on the board, I notice the RX-2 chip. Out of curiosity, I decide to google for this chip. To a pleasant surprise, I found RX-2/TX-2 Datasheet in Chinese and guide for exactly the board in the car and remote.
Decide to replace RX-2 in the car with Arduino so the H-Bridge on board can be reused and the RF for the remote can still work. Still trying to figure out what I am going to do with those remote control signal. A few facts about RX-2/TX-2 chip I found is that the RC frequency can be adjusted by different resistance from 100K to 500K Ohm between OSCI/OSCO pins.
January 9th, 2011 § § permalink
Been researching wireless solutions to transmit in real-time sensor and decision information from ART in addition to possibly enabling minimal controls (on/off/behavior switch) and perhaps even wireless firmware updates.
My criteria:
- Low-cost (<200RMB, preferably <100RMB)
- Simplex or half-duplex OK
- Low-bandwidth (>1,200 bit/s)
- Low-power (<100 mAh)
- Medium-range (500m-1000m)
- TTL or SPI interface
I know that 2.4Ghz is good worldwide (such as what the Nordic nRF240L uses) but that has a very limited range (50m-100m). So is Bluetooth and to a certain degree Wifi (and they are pretty expensive too).
There are these:
- PTR8000+ [Nordic nRF905 (433/868/915MHz)]
- Laipac Tech RF 900DV(900 mhz)
- Laipac ASK Transmitters (315 mhz)
- Databridge
- JZ871 Data RF transceiver for wireless telemetry system (433 MHz or 868Mhz/915Mhz)
Last one actually looks better than the Nordic on paper, but from what I gathered the price is pretty high. I wonder about the price and why I can’t find it on Taobao…
January 7th, 2011 § § permalink
新车间开放日：休闲机器人的时代
时间: 2011年元月十六日，下午一点到五点
地点：徐汇区永嘉路50号新单位（近陕西南路）
费用: 免费
随着数字零件价格的降低加上丰富的开源机器人软件，DIY机器人已经可以当做事一个假日的休闲活动。这次的新车间开放日我们将介绍几个会员DIY的机器人和介绍一个将要举办的积极人竞赛。如果你对机器人有兴趣，请在这个周日加入我们，一起了解现代机器人的发展，一起讨论如何玩机器人。如果有小孩的话，非常欢迎他们一起来参加这个的活动。
- 关于HC Robot
http://code.google.com/p/hcrobot/
- 关于A.R.T.
http://xinchejian.com/?p=289
在这里注册
Robot Contest Kick Off- Xin Che Jian Open House: the coming of entertainment robots
Time: 13:00 – 17:00, Jan 16, 2011
Location: Xindanwei, 50 Yongjia Rd
Cost: Free, Open house
Building robots is fun and building robots to race is doubling the fun! The era of robot building as hobby has come and we plan to celebrate the beginning of this era with a festive robot contest. At this Xin Che Jian open house, we will present a few home built robots and the plan for a contest for discussion. Come and see how you can get involved! If you are a parent, bring the kids! We are sure they will love the robots!
Robots on site:
- HC Robot: open source home help robots
http://code.google.com/p/hcrobot/
- A.R.T.
http://xinchejian.com/?p=289
Register for the event here
January 6th, 2011 § § permalink
Happened to stop by Xin Che Jian with my camera today and I thought I should take some A.R.T. glamour shoots.
December 30th, 2010 § § permalink
Photos from the new robot contest for kids in Shanghai called RoboMaster. Looks a lot of fun!
December 20th, 2010 § § permalink
Saw Ricky came in with a RC car today and kicked his Robot RC car project. Very cool! Read more…
Also, spoke NPI today about hosting robot RC car race in their place in the future. A robot F-1! That would be fun.
December 20th, 2010 § § permalink
Wow, this is pretty big news for us at Xinchejian. Google releases Android robot libraries. In China, we have access to the biggest variety of Android devices, all thanks to the Shanzhai industry.
(Via DIYDrone.)
