Posts Tagged usb
Old mobile phone, RS232
by someone16 on Apr.30, 2009, under Electronics
A few days ago a friend send me an old mobile phone for using in a project about weather information in a remote location.
On the internet I found which pins on telephone are TX, RX, GND. I simply connected them to USB -> RS232 cable, when I found out that I must destroyed it last time by shortcut between ground and 5V.
I remembered about a project in which author used V-USB firmware only implementation of USB fot AVR devices to create home made USB to RS232 converter. In a few minutes I had a working converter (Thanks toOsamu Tamura at Recursion Co., Ltd.)
I connected everything and result was ... garbage. On HyperTerminal I received only garbage. I remember about using MAX232 chip for converting TTL levels to computer levels and vice versa. Tried with this chip and the same thing, of course a little bit different garbage, but still garbage and nothing useful.
So I give up for today ... tomorrow is a new day and maybe I'll have more luck. I could try connecting AVR with code for serial communicating to see if there is a problem on converter/computer or somewhere else.
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:avr Electronics max232 mobile phone rs232 usb
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On the internet I found which pins on telephone are TX, RX, GND. I simply connected them to USB -> RS232 cable, when I found out that I must destroyed it last time by shortcut between ground and 5V.
I remembered about a project in which author used V-USB firmware only implementation of USB fot AVR devices to create home made USB to RS232 converter. In a few minutes I had a working converter (Thanks toOsamu Tamura at Recursion Co., Ltd.)
I connected everything and result was ... garbage. On HyperTerminal I received only garbage. I remember about using MAX232 chip for converting TTL levels to computer levels and vice versa. Tried with this chip and the same thing, of course a little bit different garbage, but still garbage and nothing useful.
So I give up for today ... tomorrow is a new day and maybe I'll have more luck. I could try connecting AVR with code for serial communicating to see if there is a problem on converter/computer or somewhere else.
Wireless Connection
by someone16 on Apr.27, 2009, under Electronics
I haven't decided yet what wireless connection I am going to use to connect car to laptop.
I have a lot of options but every option have some advantages and disadvantages.
a) using old HP laptop - good options, i can connect webcam, additional hardware without a problem. Cons: battery has bad autonomy (about 20 minutes), weight, WLAN connection (as far as I know PCMCIA connector doesn't work, so I need to buy USB WLAN module
New battery is at least 100€ and USB WLAN module is 40€.
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:Electronics transceivers usb xbee
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I have a lot of options but every option have some advantages and disadvantages.
a) using old HP laptop - good options, i can connect webcam, additional hardware without a problem. Cons: battery has bad autonomy (about 20 minutes), weight, WLAN connection (as far as I know PCMCIA connector doesn't work, so I need to buy USB WLAN module
New battery is at least 100€ and USB WLAN module is 40€.
b) using RFM10 wireless transceiver - i have 2 transceivers at home but they are in SMD and they can be connected to microcontroller only by SPI interface which is really hard to write a firmware code for
c) using XBee - great range, a lot of resources for it but a little higher price (20€ a piece and I need two of them)
I'll probably use XBee modules but they are just too expensive. My goal is to build a car controlled by laptop for under 100€. Cost of these modules is a real set back for this project.