 | | Re: Battery level monitoring?
|
|
(...) For anyone else interested, I came across a description by Fred of a modification to the Miniboard that describes how to cut a track on the board to allow analog battery level monitoring. Unfortunately, the picture is missing from the page: (...) (28 years ago, 16-Apr-96, to lugnet.robotics.handyboard)
|
| |
| | Sonar sensitivity to 'Curtains'
|
|
I gave my Polaroid Sonar the curtain test and it passed. Someone suggested that Sonar could not see curtains. Not only does it see curtains, it also sees a towel, a handkerchief, a kleenex, and, get this, a piece of free hanging string. My bot is (...) (28 years ago, 16-Apr-96, to lugnet.robotics.handyboard)
|
| |
| | RE: h-bridges, current info
|
|
The answer is yes, but it isn't as useful. BJTs (Bipolar Junction Transistors) are current based devices, if you look at the 'base' input to the transistor as a pipe, for NPN devices there needs to be current flowing "into" the base for them to turn (...) (28 years ago, 15-Apr-96, to lugnet.robotics.handyboard)
|
| |
| | RE: High current motors
|
|
Jeff is correct, after looking at the schematics for the motor driver my circuit won't work. You will have to wire two sides of the motor driver output to the 2907's with back to back diodes. I'll draw up a schematic and post it. (In my original (...) (28 years ago, 15-Apr-96, to lugnet.robotics.handyboard)
|
| |
| | RE: Ultrasound Range-Finding
|
|
(...) The IR sensors on the robot I built have an effective range of about 4 feet. The "downside" of IR sensors are that they are much more difficult to scale in terms of distance. I used a PIC chip to do both illumination and error elimination and (...) (28 years ago, 15-Apr-96, to lugnet.robotics.handyboard)
|
| |
| | Re: High current motors
|
|
(...) On the handy board, this is different, isn't it? I didn't think that the center pin was V+... In fact, isn't it not a connection at all? (...) Isn't this supposed to read, "Now connect the COLLECTOR of one 2N2907 to the base of Q1, connect the (...) (28 years ago, 15-Apr-96, to lugnet.robotics.handyboard)
|
| |
| | RE: Ultrasound Range-Finding
|
|
(...) Don't most IR sensors have a limited useful range, though? I understood that it was difficult to get more than 2-3 inches from an IR sensor - can they be made long-range sensitive? Sean R. Cunningham MSI Consulting Group (URL) (28 years ago, 15-Apr-96, to lugnet.robotics.handyboard)
|
| |
| | RE: Ultrasound Range-Finding
|
|
(...) For which I have only one comment, "Curtains". Yes, IR can see curtains, ultrasonics cannot. --Chuck (28 years ago, 15-Apr-96, to lugnet.robotics.handyboard)
|
| |
| | New Battery Hack + Charger
|
|
This is in reference to the Motor Voltage Hack on the HandyBoard. In considering the prospect of including the new battery pack in the charge circuit, we should consider the following. 1) The machanics of charging a NiCad is to force a voltage that (...) (28 years ago, 15-Apr-96, to lugnet.robotics.handyboard)
|
| |
| | Re: Ultrasound Range-Finding
|
|
I have my Polaroid Sonar connected and running. It seems to work perfectly. There is no additional circuitry required. In fact it works so well, I am probably not going to install the IR system, at this time. Larry (...) (28 years ago, 15-Apr-96, to lugnet.robotics.handyboard)
|
| |
| | RE: motor voltages
|
|
The most efficient way to do this is to use a "step down" regulator. These small switching regulators can efficiently lower the voltage while maintaining the current requirements. Maxim sell several chips that do this however you will be limited to (...) (28 years ago, 15-Apr-96, to lugnet.robotics.handyboard)
|
| |
| | Re: Assembler
|
|
(...) I thought I would add for all who haven't read the IC manual, (like me a few weeks back), that it clarifies alot of the capabilities and workings of the handyboard. And that it only takes like one night of bedtime reading so it's kinda short (...) (28 years ago, 15-Apr-96, to lugnet.robotics.handyboard)
|
| |
| | Re: motor voltages
|
|
I think what you need is only a simple VR( voltage regulator) It kinda resembles a transitor in appearance). I'm curious to know whether this is all you need. I'm not an EE either so I wonder if you need heat sinks or capacitors or something. ? (...) (28 years ago, 15-Apr-96, to lugnet.robotics.handyboard)
|
| |
| | Re: Ultrasound Range-Finding
|
|
I looked arround and this is the cheapestI've found so far. If you go to the various ultrasound specialists, they want an arm and a leg...make that your a torso too. I believe these polaroid things are manufactured in LARGE production conpared to (...) (28 years ago, 15-Apr-96, to lugnet.robotics.handyboard)
|
| |
| | Re: Motor Voltage Hack
|
|
(...) Yes, I believe so. I was thinking of that last night but haven't had a chance to look it over. I think you would need to temporarally reconnect the cut with some form of voltage drop,(several diodes in series ?) when the charger is connected. (...) (28 years ago, 15-Apr-96, to lugnet.robotics.handyboard)
|
| |
| | Re: Smoothing capacitors on motors?
|
|
(...) 0.1 uF Use ceramic disk capacitors because they can withstand the high voltage of the spikes. -f (28 years ago, 15-Apr-96, to lugnet.robotics.handyboard)
|
| |
| | Re: Assembler
|
|
(...) I'm pretty sure that files assembled this way will work with the freeware IC as well. Please note one big GOTCHA with ICB files. On the MS-DOS platform, the ICB files must have Unix-style line termination. OK, what does that mean. In a text (...) (28 years ago, 15-Apr-96, to lugnet.robotics.handyboard)
|
| |
| | Re: Assembler
|
|
(...) 1. please read the IC manual, which is now localized for the Handy Board. this explains how the ICB system works in detail. look on the HB home page to find the IC manual. 2. yes, you need as11_ic. mac and unix versions are readily available. (...) (28 years ago, 15-Apr-96, to lugnet.robotics.handyboard)
|
| |
| | Smoothing capacitors on motors?
|
|
I am using a couple of 6V motors and I have read that it is a good idea to put a capacitor across the terminals of each motor. Although I see references to this practice all over, no one has indicated what ratings this capacitor should have. Does (...) (28 years ago, 15-Apr-96, to lugnet.robotics.handyboard)
|
| |
| | Re: Motor Voltage Hack
|
|
(...) [snip] (...) Thanks for this great tip - Can we also tie this second battery pack into the nicad charging system somehow? Sean R. Cunningham MSI Consulting Group (URL) (28 years ago, 15-Apr-96, to lugnet.robotics.handyboard)
|
