Dawn Robotics Forum

Hi there

I recently purchased the Pi robot bundle,which is now assembled. I downloaded the disk image and mounted onto an SD.The pi boots up fine,but I am wondering if the wireless Edimax dongle is working.

First off it lights up and flashes away ,but when I go into WIFI config,it doesnt show the adapter ? Ive done an ifconfig,and it does mention wlan0 link encap ethernet ,and theres an inet and bcast address.

I have tried pinging the address from my pc but get nothing back.

Any ideas whats wrong here ?

Gary

Hi Gary,

Welcome to the forum. Sorry for the delayed reply.

The Wifi dongle is working as an access point, so that may be the reason it's not showing up as you expect?

When you view nearby WiFi networks with a device such as a phone, do you see a network called Pi_Mini_Robot? Normally you'd connect to that network (password Raspberry with a capital R) and control the robot by navigating to its IP address 192.168.42.1 with a webbrowser such as Chrome or Firefox.

If you'd like to make the robot connect to your router then you'll need to edit the file /etc/network/interfaces. You can open it by running

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sudo nano /etc/network/interfaces

and editing it to look something like this

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auto lo

iface lo inet loopback
iface eth0 inet dhcp

allow-hotplug wlan0

iface wlan0 inet dhcp
   wpa-ssid "Router_SSID"
   wpa-psk "Router_Password"

You also need to disable the access point functionality. This can be done in a hacky way by running

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sudo nano /etc/hostapd/hostapd.conf

and changing the driver line to read

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driver=disabled

Hope that helps and is what you were looking for. Apologies if I've misunderstood.

Regards

Alan

Aaaaah,got it,almost ! I seem to be having the same problem that another poster has mentioned here. the PI_MINI_ROBOT wifi shows up,I can connect easily enough.The connection remains solid until I try the access point 142.168.42.1.The controls load up on the browser,but then the connection drops out,the dongle stops flashing,and the wifi point no longer shows .

Where to next !!!


Gary

Update.Its something to do with the motors. With one connected,I can make the bot spin round in circles,and the connection doesnt drop. With both motors connected,it goes for a few seconds,stops,and we lose wifi.

Hi Gary,

Sorry for the delayed reply again. I've been very snowed under this week, but furture replies should hopefully be quicker.

It sounds to me like a power problem. How exactly are you powering your robot? Is it with AA batteries, and if so, what type of batteries are you using? i.e. rechargeable or non-rechargeable?

Regards

Alan

Yep without question this is power. I bought a teknet power bank to run this. When the power is routing from teknet (2.1a outlet) to driver,then driver to pi via ubec,theres the problem. when you connect to the web servers page,and try to drive both wheels,it seems very sluggish and cuts out after a few seconds,the wifi drops out ( driver board stopped maybe ?). The pi still runs no problem Ive got it hooked into a monitor.

I tried running the power for the driver straight from mains ( usb power plug with the driver usb lead plugged in) and another mains usb supply to run the pi,cutting out the ubec altogether. after connecting to the web server and trying both wheels,it runs no problem ( holding the unit up and letting the wheels run ) no drop out and no sluggish power.


What do you reckon Paul ?

UPDATE - success ! Me not reading instructions properly. I had the ubec in amongst all that ,where running off powerbank. Power issues now fine .

but . . . .

controls are really retarded. Up/forward sends it into a spin,as does back/reverse. Left and right can get both wheels running to give you straight line driving but its very fiddly finding that sweet spot. I will automaticaly assume its me doing something wrong again !


Any pointers ?

Gary

Hi Gary,

Ah yes, that mistake has been made before with the batteries. I've updated the instructions to try to make them clearer, and I think that the update may have been after you bought the kit.

Controls can definitely be a bit twitchy and take some time to get used to. No 2 DC motors will run at exactly the same speed when given the same voltage, and you can balance out the motors on your robot a bit by going to 192.168.42.1/config.html and playing with the 'Left Motor Speed Scale' setting on the motors tab. Also if you only move the movement joystick forward a small amount then you should find that the robot drives forward much more slowly, and this makes it a bit easier to control the robot.

Regards

Alan