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by mikronauts
Wed Dec 12, 2018 4:17 pm
Forum: Python
Topic: Reading PDM data @ 2MHz with Raspberry Pi + pigpio (Python)
Replies: 25
Views: 6039

Re: Reading PDM data @ 2MHz with Raspberry Pi + pigpio (Pyth

You are most welcome. HI, Thanks for response I shall try 4 bit one That is because those chips don't have them... I would use a 4 bit binary counter driven by the shit clock signal, look for a change on q3 (highest bit) which would indicate 8 clock pulses have been seen. Thank you very much for the...
by mikronauts
Tue Dec 11, 2018 5:30 pm
Forum: Python
Topic: Reading PDM data @ 2MHz with Raspberry Pi + pigpio (Python)
Replies: 25
Views: 6039

Re: Reading PDM data @ 2MHz with Raspberry Pi + pigpio (Pyth

That is because those chips don't have them... I would use a 4 bit binary counter driven by the shit clock signal, look for a change on q3 (highest bit) which would indicate 8 clock pulses have been seen. I would use a 74hc299 or 74hc595 (google for sample usage) Hello I am Vipin Please may I have t...
by mikronauts
Tue Dec 11, 2018 2:55 pm
Forum: Troubleshooting
Topic: About ADC and PWM
Replies: 2
Views: 65

Re: About ADC and PWM

If the hat uses an ADC chip, you can't reprogram it to get a pwm output. If the hat uses a microcontroller for analog input, then if the chip lets you change modes for the pin to pwm output, and the firmware supports it ... maybe, however if the manual does not say the hat can do that, forget it. Ju...
by mikronauts
Tue Dec 11, 2018 2:06 am
Forum: Automation, sensing and robotics
Topic: robot controller
Replies: 15
Views: 287

Re: robot controller

One example: https://www.amazon.com/Venom-5000mAh-Battery-Universal-Traxxas/dp/B000VUF3O2 There is a hobby shop in your town https://www.yellowpages.com/peculiar-mo/mip/peculiar-game-530737830?lid=530737830 Took me 10sec to find via google I live in a little town you have never heard of known as har...
by mikronauts
Mon Dec 10, 2018 6:59 pm
Forum: Automation, sensing and robotics
Topic: robot controller
Replies: 15
Views: 287

Re: robot controller

My friend, go to a local rc hobby shop, or google for 7.4v rc battery pack, 2ah :) I do drive by help posts here im my coffee breaks and when compiling code or flashing chips, I usually do not have time to also do the googling leg work for those I help. also maybe a link because I am new to this?
by mikronauts
Mon Dec 10, 2018 6:34 pm
Forum: Python
Topic: Reading PDM data @ 2MHz with Raspberry Pi + pigpio (Python)
Replies: 25
Views: 6039

Re: Reading PDM data @ 2MHz with Raspberry Pi + pigpio (Pyth

I would use a 74hc299 or 74hc595 (google for sample usage) Thank you for your response. I realize that it may not be possible to acquire a single bit @ 2MHz. But, if I use a 8-bit shift register, then I would have to acquire 8 bits or 1 byte every 2M/8 = 250kHz. A shift register also sends out a log...
by mikronauts
Mon Dec 10, 2018 6:32 pm
Forum: Automation, sensing and robotics
Topic: robot controller
Replies: 15
Views: 287

Re: robot controller

Assuming 1A load while moving @ 7.4V, with two motors 2 * 1A * 0.5h is 1amp-hr capacity for an rc nimh or nicad 7.4v battery pack But, it is best to test this in real life, as it depends on weight of robot, surface you are on, speed and more. Btw, use a separate usb battery pack for the pi etc now a...
by mikronauts
Fri Dec 07, 2018 1:55 pm
Forum: Automation, sensing and robotics
Topic: robot controller
Replies: 15
Views: 287

Re: robot controller

From chassis spec Rated Voltage: 6 V Operating Voltage Range 2~7.5V From driver board Voltage supply: DC 7 ~ 24 V Voltage supply limit: 6.5 ~ 27 V Note motor drivers drop 0.5v ... 1v from their supply voltage before "feeding" the motor However you can get any driver board as long as it can supply 2....
by mikronauts
Fri Dec 07, 2018 3:18 am
Forum: Automation, sensing and robotics
Topic: robot controller
Replies: 15
Views: 287

Re: robot controller

Good looking chassis!

From their site, I would get

https://www.dfrobot.com/product-1534.html
Will5455 wrote:
Fri Dec 07, 2018 3:00 am
yep meant motor controller not rbot controller!

https://www.dfrobot.com/product-1477.html
this is the set of stuff
by mikronauts
Fri Dec 07, 2018 1:04 am
Forum: Automation, sensing and robotics
Topic: robot controller
Replies: 15
Views: 287

Re: robot controller

Do you mean motor driver? PWM allows speed control with geared motors. Or do you mean stepper motors or servo's? You should also post the maximum current your motor may need. Please post a link to the motors web page. Does anybody know of a good robot controller capable of 6v with variable speed who...
by mikronauts
Thu Dec 06, 2018 5:48 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Long SPI distance problem with 2 Slaves.
Replies: 1
Views: 64

Re: Long SPI distance problem with 2 Slaves.

SPI is meant for short distances (examples: on the same pcb, or daughter board plugged into pcb) Sometimes (if running at a low enough data rate) you can abuse the spec and run faster, but you will be very susceptible to corrupted data due to electrical noise. Simplest solution for you is to use two...
by mikronauts
Wed Dec 05, 2018 7:39 pm
Forum: Automation, sensing and robotics
Topic: Experience with robot-core controller?
Replies: 5
Views: 553

Re: Experience with robot-core controller?

Thanks! Site should be back up later today, it was hacked again while I was away from my office (yet another wordpress plugin exploit) Hi there, and sorry for HI-Jacking! Mikronauts, i have readed one of your great artikle and has planned to build a project based around 16 pcs of MCP3208 to one 74HC...
by mikronauts
Sun Dec 02, 2018 7:01 pm
Forum: Other projects
Topic: Occupancy Detection
Replies: 4
Views: 147

Re: Occupancy Detection

I have used PIR sensors for this. When I detected motion, I flagged that area as occupied for half an hour. When there was no further motion detected, area was flagged as unoccupied. This worked fairly well for a smart house, back in 1984 :) Hi all Been chatting about this in another thread and some...
by mikronauts
Thu Nov 29, 2018 4:54 pm
Forum: General discussion
Topic: WE ARE CURRENTLY EXPERIENCING HIGH TRAFFIC. WE'LL BE BACK SHORTLY.
Replies: 19
Views: 1461

Re: WE ARE CURRENTLY EXPERIENCING HIGH TRAFFIC. WE'LL BE BACK SHORTLY.

Idea: make a table evey 10 minutes that holds only last 3 months of posts, and do the select against that. We are aware, it was reported over th e weekend to the webteam. We've been in touch with Mythic and are discussing ways of improving things. The main issue is that the post database is getting ...
by mikronauts
Tue Nov 27, 2018 4:00 pm
Forum: General discussion
Topic: protoboards for RPi - opinions / sugestions wanted
Replies: 1
Views: 92

Re: protoboards for RPi - opinions / sugestions wanted

I market a fairly large number of prototyping boards, some generic, some Pi specific. See my tindie store at https://www.tindie.com/search/?q=Mikronauts I believe the 3"x4" boards are very close to what you are looking for (if smaller) as they have 3 pin pads and support 40 pin headers. My 26 pin Ez...
by mikronauts
Fri Nov 02, 2018 12:22 pm
Forum: General discussion
Topic: A good battery for the Pi 3B+?
Replies: 40
Views: 1189

Re: A good battery for the Pi 3B+?

Sorry, I meant not pi3b+'s ... I inadvertantly left out the '+' I am still waiting for pi3a or pi3a+ boards. (Typos mostly due to using a tzblet to post, as I am away from my office) Fyi, I run Pi3's (not 3b) off usb power banks all the time, so I see no reason a 3b would not run off a good power ba...
by mikronauts
Fri Nov 02, 2018 3:21 am
Forum: General discussion
Topic: A good battery for the Pi 3B+?
Replies: 40
Views: 1189

Re: A good battery for the Pi 3B+?

Fyi, I run Pi3's (not 3b) off usb power banks all the time, so I see no reason a 3b would not run off a good power bank. I will try it soon, I need to test a 3b based robopi bog anyway. A regular phone charger battery pack will do what you want, but the hard part is finding one that actually holds i...
by mikronauts
Thu Nov 01, 2018 5:38 pm
Forum: Automation, sensing and robotics
Topic: [Help] - Arduino to Pi project
Replies: 3
Views: 191

Re: [Help] - Arduino to Pi project

Try serial comm to the arduino, and possibly Pygame for the hmi on the Pi. Hi, I'm new on this forum, and want to thanks you all in advice for all the help (and patinece). Just for let you know about my grade of knowledge, I tell you that I'm an automation engineer, working mostly on programming PLC...
by mikronauts
Tue Oct 23, 2018 5:05 pm
Forum: General discussion
Topic: Oh damn, it's happened! Charging a lot of pis?
Replies: 10
Views: 645

Re: Oh damn, it's happened! Charging a lot of pis?

I would use atx power supplies, 5v directly, and 12v regulated down to 5v. I’m actually kitted out quite well with variable power supplies, oscilloscopes, soldering kit and all sorts of magical electrical gubbins, but most of my electrical knowledge is invested in the world of high powered electric ...
by mikronauts
Mon Oct 22, 2018 3:17 pm
Forum: Automation, sensing and robotics
Topic: Connecting Pi to reed switches on long cable
Replies: 10
Views: 926

Re: Connecting Pi to reed switches on long cable

Not likely (at least not reliably) Use a transistor (or mosfet or ssr) to switch 12v, and an opto isolator to read it. To clarify, 12V is what the switches are designed for. I have no 12V in my system at present, all I have is a Pi, some cable and a reed switch. If I put 3.3V down 25m of wire, then ...
by mikronauts
Mon Oct 22, 2018 3:14 pm
Forum: Automation, sensing and robotics
Topic: Using RPI link with PLC
Replies: 2
Views: 589

Re: Using RPI link with PLC

Which plc?

Depending on supported protocol, it could be reasonably easy.

Think modbus/tcp, NOT OPC
robinshion wrote:
Sun Oct 21, 2018 11:42 pm
Does anyone have an idea about using RPI ethernet port link to PLC ethernet port, that act as OPC or something else to get data collection?
by mikronauts
Thu Oct 11, 2018 5:54 pm
Forum: Beginners
Topic: ADC in python, change sampling time
Replies: 2
Views: 108

Re: ADC in python, change sampling time

you will get a lot of variance if you leave the input floating

Tie unused inputs to ground.
by mikronauts
Thu Oct 04, 2018 2:30 pm
Forum: Automation, sensing and robotics
Topic: Experience with robot-core controller?
Replies: 5
Views: 553

Re: Experience with robot-core controller?

I am not familiar with that interesting board ... I like its dc-dc converter (I use off-board converters or BEC's) Depending on your applications you may wish to take a look at http://www.mikronauts.com/raspberry-pi/pi-droid-alpha/ (10 bit 8 ch adc, L293d motor driver, servo control) http://www.mikr...
by mikronauts
Wed Sep 26, 2018 10:36 pm
Forum: General discussion
Topic: Unable to read adc data from SPI0 bus in raspberry pi 3
Replies: 10
Views: 372

Re: Unable to read adc data from SPI0 bus in raspberry pi 3

Take a peek at my article at http://www.mikronauts.com/raspberry-pi/raspberry-pi-analog-to-digital-conversion-experiments-and-howto/ It does need an external 3:8 demux, but it allows you to use just one of the SPI /CS signals and decode to eight SPI peripherals by using three GPIO's to decide which ...
by mikronauts
Wed Sep 05, 2018 5:02 pm
Forum: Beginners
Topic: Completely new to Raspberry Pi. Need to build logger for work.
Replies: 21
Views: 779

Re: Completely new to Raspberry Pi. Need to build logger for work.

Google "raspberry pi data logging", you will find a lot of helpful information. Other questions you may have to consider: what does it log to: serial output, network, display, …? are these existing sensors, or a new build? Interfacing to some older sensors can be challenging, and you may need specia...

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