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by mikronauts
Sat Nov 25, 2017 4:43 pm
Forum: Add-ons
Topic: Anybody interested in talking direct! to IDE/SATA?
Replies: 23
Views: 986

Re: Anybody interested in talking direct! to IDE/SATA?

We did some I/O test on the pi many, many years ago. (My god, I am getting old...) At 100 MHz the signal looked more like a sine wave. So my guess is that 50-75 MHz is about the limit. At 16 bits wide that is 100-150 Mbyte/sec. 100MB-150MB/sec would still be sweet :) At the time I wrote that code, ...
by mikronauts
Wed Nov 22, 2017 12:52 am
Forum: Add-ons
Topic: Anybody interested in talking direct! to IDE/SATA?
Replies: 23
Views: 986

Re: Anybody interested in talking direct! to IDE/SATA?

Hi Gert, Well done! 44MBytes/sec over a channel independent from USB is a nice achievement. I was looking into doing the same thing, and have been trying to get actual register level documentation from RPF, Broadcom reps etc - no joy. A couple of kind RPF employees pointed me at the NAND kernel driv...
by mikronauts
Mon Aug 28, 2017 10:36 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: SPI or BitBang via GPIO to 5v device and vice-versa
Replies: 45
Views: 3523

Re: SPI or BitBang via GPIO to 5v device and vice-versa

it's not the feeding

it is the responding witin 1us

google:

hard real time

6502 bus cycle documentation
by mikronauts
Mon Aug 28, 2017 7:04 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: SPI or BitBang via GPIO to 5v device and vice-versa
Replies: 45
Views: 3523

Re: SPI or BitBang via GPIO to 5v device and vice-versa

You cannot get a guaranteed 1us response from a pi like that. Not even 2us (as I recall that 500khz was the maximum respone rate) Add an fpga or dual ported memory between the apple bus and a pi (if you need to use a Pi) Thanks for replying! What I'm looking for is to implement a peripheral card on ...
by mikronauts
Mon Aug 28, 2017 6:39 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: SPI or BitBang via GPIO to 5v device and vice-versa
Replies: 45
Views: 3523

Re: SPI or BitBang via GPIO to 5v device and vice-versa

Hi, Sorry, basically impossible as asked... but it really depends on exactly what you are trying to do. 1) pi emulating ram for a 6502 ... impossible without a big fpga that has enough block ram and level shifters and this case the fpga emulates the memory, which the pi could also access 2) run appl...
by mikronauts
Sat Aug 19, 2017 10:55 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Pi0 - 2 USB devices without HUB
Replies: 4
Views: 488

Re: Pi0 - 2 USB devices without HUB

good point

I was taking the op's need for two usb devices at face vale.

I will now go and mske more coffee :)
Martin Frezman wrote:
Sat Aug 19, 2017 9:23 pm
Getting a hub would violate one of the premises.

Instead, get a Pi Zero W - which has wireless built-in. Then you don't need to have an external WiFi dongle.
by mikronauts
Sat Aug 19, 2017 9:15 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Pi0 - 2 USB devices without HUB
Replies: 4
Views: 488

Re: Pi0 - 2 USB devices without HUB

you need a new pi and add a hub
by mikronauts
Wed Aug 16, 2017 3:57 pm
Forum: Python
Topic: HC-SR04 always return 1.0
Replies: 4
Views: 486

Re: HC-SR04 always return 1.0

You can try my article/tutorial: http://www.mikronauts.com/raspberry-pi/gpio-experiments/raspberry-pi-and-hc-sr04-distance-sensor-interfacing-with-c-and-python/ Hi, I have trying to run the example in this tutorial: https://www.raspberrypi.org/learning/physical-computing-with-python/distance/ Howeve...
by mikronauts
Tue Aug 01, 2017 11:17 pm
Forum: Automation, sensing and robotics
Topic: Multiplexing Mabotix Ultrasonic Sensors with Pi
Replies: 5
Views: 591

Re: Multiplexing Mabotix Ultrasonic Sensors with Pi

You are welcome. with 16 analog inputs, easiest way is to use two mcp3008 with ce0 to one ce1 to the other miso mosi sclk to both this assumes you do not need any more spi devices it is also now possible to use other gpio for chip selects with dt-overlay if you want to run the sensors at 5v, run the...
by mikronauts
Tue Aug 01, 2017 5:45 pm
Forum: General discussion
Topic: Raspi hat blocks all the gpio pins
Replies: 32
Views: 2165

Re: Raspi hat blocks all the gpio pins

As alphanumeric said, you can add a prototyping board with a stacking header between the Pi and the Hat.

Adafruit has such a prototyping board.

So does Mikronauts (working on uploading the product pages) basically a 40 pin gpio version of my EZasPi 26 pin boards :-)

Best Regards,

Bill
by mikronauts
Tue Aug 01, 2017 5:43 pm
Forum: Automation, sensing and robotics
Topic: ADXL 345 and duplicate readings
Replies: 7
Views: 685

Re: ADXL 345

Perhaps the sensor has filtering limiting you to 20-30 updates per second?
by mikronauts
Tue Aug 01, 2017 5:41 pm
Forum: Automation, sensing and robotics
Topic: Multiplexing Mabotix Ultrasonic Sensors with Pi
Replies: 5
Views: 591

Re: Multiplexing Mabotix Ultrasonic Sensors with Pi

1) can you post a link to the product page for the exact sensor you have? 2) if it is analog output, you will need an ADC (or two) to connect to your Pi See http://www.mikronauts.com/raspberry-pi/raspberry-pi-analog-to-digital-conversion-experiments-and-howto/ 3) or you can use one ADC, and an exter...
by mikronauts
Mon Jul 31, 2017 7:31 pm
Forum: Troubleshooting
Topic: GPIO pins sensing inputs
Replies: 3
Views: 246

Re: GPIO pins sensing inputs

if your switch connects to ground, you need to pull up the pin to 3v3, say with 10k resistor.

if your switch connects to 3v3, you need to pull down the pin to gnd, say with 10k resistor.
by mikronauts
Thu Jul 27, 2017 4:09 pm
Forum: C/C++
Topic: MCP23S17, Wiringpi or another library
Replies: 14
Views: 1102

Re: MCP23S17, Wiringpi or another library

Why on earth would you want to do that?

Save the other CS for another peripheral, you can use up to eight MCP23SXX on one CS.
pinballsp wrote:
Thu Jul 27, 2017 3:31 pm
 
Thanks DougieLawson, but with WiringPi I do not see how may I config two MCP23s17, both with same address but different Chip Select, in same SPI bus.

 
by mikronauts
Mon Jul 24, 2017 8:30 pm
Forum: Beginners
Topic: Using Rotary Encoder to measure the distance
Replies: 1
Views: 213

Re: Using Rotary Encoder to measure the distance

google 'python odometry'
by mikronauts
Wed Jul 19, 2017 3:18 pm
Forum: General discussion
Topic: Powering exteranl 3.3V device
Replies: 5
Views: 513

Re: Powering exteranl 3.3V device

I've read that the original A/B had about 50mA of elbow room left from the on-board 3v3 regulator. Newer Pi's may allow more, however if the 3v3 regulator draws too much, the 5V can be pulled too low, leading to the dreaded lightning symbol indicating low voltage. How much you can draw depends on: -...
by mikronauts
Mon Jul 17, 2017 6:58 pm
Forum: Compute Module
Topic: Expandable baseboard (slot system) for CM3
Replies: 8
Views: 917

Re: Expandable baseboard (slot system) for CM3

Imre, I am probably stating the obvious here... 1) You do realise the CM3's pins do not form a "bus" in computer terms? It would be possible to emulate one, but it would be painfully slow. 2) Multiple CM3's could form a cluster, but you would need to add Ethernet PHY's and an ethernet switch It woul...
by mikronauts
Sun Jul 16, 2017 4:19 pm
Forum: Beginners
Topic: help a noob control 8 motors and a sensor
Replies: 7
Views: 567

Re: help a noob control 8 motors and a sensor

you need to figure out the mass of the objects you want to move before you can find the motors you need
by mikronauts
Wed Jul 12, 2017 5:56 pm
Forum: General discussion
Topic: Password Protect SD Card?
Replies: 20
Views: 1496

Re: Password Protect SD Card?

Google "usb protection dongle"
by mikronauts
Wed Jul 12, 2017 5:31 pm
Forum: General discussion
Topic: Password Protect SD Card?
Replies: 20
Views: 1496

Re: Password Protect SD Card?

Can't be done. Also would not protect against image copying. If you are worried about copying, add an appropriate USB key dongle. Thanks, I would like to password protect the sd card so someone can't plug the sd card into a computer and get the contents but if it is plugged in to a certain sd card i...
by mikronauts
Fri Jul 07, 2017 4:03 pm
Forum: General discussion
Topic: No more WDLabs?
Replies: 21
Views: 2105

Re: No more WDLabs?

Too bad.

I just received my PiDrive 375GB.
W. H. Heydt wrote:I have received an e-mail from WD Labs. The shutdown is not a rumor.
by mikronauts
Fri Jun 30, 2017 4:40 pm
Forum: Raspbian
Topic: PiBakery
Replies: 9
Views: 1119

Re: PiBakery

This looks like a nice project! Two requests: 1) Linux support - I don't run MacOS, and I run Windows as little as possible :) 2) Source tarball generation - have Pi bakery generate a shell script that would download all the sources for the Raspbian configuration that it generates, and have the scri...
by mikronauts
Fri Jun 30, 2017 4:31 pm
Forum: General discussion
Topic: Pi Zero now available in multiples !
Replies: 15
Views: 1669

Re: Pi Zero now available in multiples !

The one per customer of the bare unit has NOT been lifted.
mikerr wrote:With the lifting of the 1 per customer limit it now becomes a proper product IMO
by mikronauts
Sat Jun 24, 2017 12:41 am
Forum: Networking and servers
Topic: Running multiple pi's on a tractor
Replies: 26
Views: 1838

Re: Running multiple pi's on a tractor

Why on earth do you need 25 Pi3's? So basically I want to run about 25 raspberry pi 3's on my tractor to monitor some stuff using the camera. Electricity-wise, I'm concerned about the different voltages that may come out of the tractor at different revs. What would be the most suitable way to overco...
by mikronauts
Wed Jun 21, 2017 4:47 pm
Forum: Graphics, sound and multimedia
Topic: Using the pi 3 as a 16+ channel DSP
Replies: 6
Views: 764

Re: Using the pi 3 as a 16+ channel DSP

It depends on what you want to do with all those I2S channels. I'd synchronise the Pi's with just one signal, possibly from a master, and transfer the data over Ethernet or USB, using a host to re-assemble/partition the channels - I would not even try to transfer the data between the Pi's over GPIO ...

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