Experience with MCP7940?

Started by Tim Wescott in sci.electronics.design6 years ago 8 replies
I2C

I'm getting the software going for a MCP7940, and the I2C interface is giving me fits. This is with software that worked fine for a couple of...

I'm getting the software going for a MCP7940, and the I2C interface is giving me fits. This is with software that worked fine for a couple of ST inertial sensors. Has anyone had success or failure with this part? I'm getting ever- deeper into this, but at the moment it appears that the data is getting written and read correctly, but I'm getting NACKs at the ends of transfers. -- ...


Sound chips that natively go to DC?

Started by Joerg in sci.electronics.design8 years ago 20 replies

Folks, The subject pretty much says it. Are there any that can at least be coaxed into DC input and output by disabling internal cancelers...

Folks, The subject pretty much says it. Are there any that can at least be coaxed into DC input and output by disabling internal cancelers and such? Should not be too drifty. The digital interface doesn't matter much, USB, SPI, whatever. Preferably not I2C but even that would be ok. 16 bit would suffice. Of course, more is better. Input to output synchronicity is important, as usual. Als...


Drivings LED with limited pins

Started by Mike Miller in sci.electronics.design8 years ago 63 replies

All, I want to be able to toggle 23 separate LEDs in my application. The design challenge is that I only have about 17 pins available on my...

All, I want to be able to toggle 23 separate LEDs in my application. The design challenge is that I only have about 17 pins available on my SoC. What are some options for this? 1.) Use another microcontroller with 23 available pins with some digital interface (spi/i2c) and then send over data to toggle the appropriate pins? 2.) Ideally I don't want to have to do additional firmware de...


ATTiny ADC and TWI

Started by bitrex in sci.electronics.design5 years ago 3 replies
I2C

Looking at the ATTiny datasheet...why oh why do they put one of the ADC channels on the SCL pin? So it seems if you want to use all four ADC...

Looking at the ATTiny datasheet...why oh why do they put one of the ADC channels on the SCL pin? So it seems if you want to use all four ADC channels, it's not possible to connect the uC to an i2c bus.


14 sensors on a stick

Started by Winfield Hill in sci.electronics.design2 years ago 39 replies

This is a stick of 14 sensors on six ICs, that's meant to go into the middle of a beehive. But it could be interesting for other uses. It...

This is a stick of 14 sensors on six ICs, that's meant to go into the middle of a beehive. But it could be interesting for other uses. It runs on low-power 3.3V, and uses a single I2C data bus. https://www.dropbox.com/sh/97gj51p03554cii/AAAk8W8yaLS7W_bp_JWde5W5a?dl=0 WRT to the choice of sensors, there's redundancy for the T + RH sensors, because we've had so much trouble wit...


Chip of the week

Started by Piotr Wyderski in sci.electronics.design4 years ago 19 replies

Mine is INA260, a voltage/current/power monitor with integrated shunt and digital I2C output. No external components required. It'd be hard to...

Mine is INA260, a voltage/current/power monitor with integrated shunt and digital I2C output. No external components required. It'd be hard to improve it any further, similarly to the WS2812 programmable LEDs which IMHO closed the chapter on RGB LED control. There are four color variants too, but conceptually it is still the same protocol. Any other ICs that hit the bullseye and you would li...


Rigol scope settings

Started by bitrex in sci.electronics.design4 years ago 27 replies

I have a shiny new Rigol DS1102E on the bench that I'm trying to set up to view transmissions on an i2c bus. There's a burst of data on the bus...

I have a shiny new Rigol DS1102E on the bench that I'm trying to set up to view transmissions on an i2c bus. There's a burst of data on the bus about once a second that I'd like to look at. Pretty sure some folks here are familiar with this series and have probably used it for this purpose before; can you recommend some settings to capture that effectively on this scope? I know, RTFM and ...


1.8 volts (max)

Started by Winfield Hill in sci.electronics.design3 years ago 29 replies

A middle-of-the-bee-hive insert, my little I2C sensor module has five sensor ICs, comprising 12 sensor channels. All running on 3.3-volts,...

A middle-of-the-bee-hive insert, my little I2C sensor module has five sensor ICs, comprising 12 sensor channels. All running on 3.3-volts, so I thought. Then my programming associate, reading the datasheets more carefully than I, pointed out one of the gas sensors was limited to 1.8 volts. What!? 1.8-volts absolute maximum!? Sheesh! Back to the drawing board, add six more pa...


Cool new 8-bitter

Started by bitrex in sci.electronics.design4 years ago 7 replies

The ATMega 4809. Hardware multiplier, 16 channel 10 bit ADC, 5 16 bit timers, 2 interrupt priority levels, atomic set/clear GPIOs,...

The ATMega 4809. Hardware multiplier, 16 channel 10 bit ADC, 5 16 bit timers, 2 interrupt priority levels, atomic set/clear GPIOs, hardware SPI/i2c, 6k SRAM and 48k Flash, and set of on-chip PLC gates. It will probably come in at about $1 in quantities of hundreds


F to bits

Started by David Lesher in sci.electronics.design4 years ago 66 replies
I2C

Seeking a packaged line (~~60hz) frequency [or period] counter with I2C or SPI output to feed a Mega2560 box. The goal is to monitor a b/u...

Seeking a packaged line (~~60hz) frequency [or period] counter with I2C or SPI output to feed a Mega2560 box. The goal is to monitor a b/u generator's speed. Suggestions? -- A host is a host from coast to coast.................wb8foz@nrk.com & no one will talk to a host that's close.......................... Unless the host (that isn't close).........................pob 1433 is busy...


test gadget

Started by John Larkin in sci.electronics.design8 years ago 17 replies

Imagine a box with a USB interface, that is full of DACs, a mux'd high-quality DVM, a bunch of logic i/os, I2C and SPI, some SSRs, a...

Imagine a box with a USB interface, that is full of DACs, a mux'd high-quality DVM, a bunch of logic i/os, I2C and SPI, some SSRs, a few programmable power supplies, all easy to control from various programming languages. An internal FPGA would be programmable through the USB port. The standard config would do the standard i/o, but it would be user reprogrammable to do special stuff, w...


isolated synchronous flyback topology idea

Started by bitrex in sci.electronics.design4 years ago 11 replies

I was reading about various isolated synchronous flyback topologies and the schemes used to sense and optimize dead time of the switches; I was...

I was reading about various isolated synchronous flyback topologies and the schemes used to sense and optimize dead time of the switches; I was thinking why not use a cheap 8 pin micro (like 50 cents) with onboard fast PWM and 10-12 bit ADC on each side, along with some kind of gate driver to drive the switches. Then communicate across the isolation barrier with each other via i2c to "kn...


Hot plugging serial EEPROM

Started by Anonymous in sci.electronics.design6 years ago 19 replies
I2C

I have an application where a large connector, likely a d-sub, will need to contain a serial NVRAM device to hold information about what is...

I have an application where a large connector, likely a d-sub, will need to contain a serial NVRAM device to hold information about what is attached to the connector. Very little storage will be needed, maybe 64 bytes or so. This connector will be hot-plugged into a product which access the NVRAM. The question that comes to mind is how will an SPI or I2C EEPROM handle hotpl


Radio communications device on I2C

Started by Anonymous in sci.electronics.design7 years ago 5 replies
I2C

Hello, I'm looking for a device which I can connect to STM32 (the one like here:...

Hello, I'm looking for a device which I can connect to STM32 (the one like here: http://www.st.com/st-web-ui/static/active/en/resource/technical/document/data_brief/DM00094498.pdf) for radio communications. I want to transmit and receive signals, encoded with AX.25. I found one here: http://www.cubesatshop.com/index.php?page=shop.product_details&flypage=flypage.tpl&product_id


How about it? Experiments of the third kind , take 999999.

Started by Jan Panteltje in sci.electronics.design10 years ago 16 replies

How about it? Experiments of the third kind , take 999999. Update Get ready for programming: I finished the hardware in the black box, made...

How about it? Experiments of the third kind , take 999999. Update Get ready for programming: I finished the hardware in the black box, made a small design change for safety: put a 1 k resistor in series with SDA, and use a 12k pull up. This is to avoid any i2c bus conflicts during software tinkering. A good practice. Had the box powered up, fixed the usual wiring errors, and everyt...


AGP30, issues with CO2 VOC sensor

Started by Winfield Hill in sci.electronics.design2 years ago 27 replies

Has anyone here used the Sensirion AGP30, a tiny I2C sensor for CO2 and VOC gases? It takes about 60mA to heat a hot plate, and it needs at...

Has anyone here used the Sensirion AGP30, a tiny I2C sensor for CO2 and VOC gases? It takes about 60mA to heat a hot plate, and it needs at least 15 seconds to start reading data. But ours is experiencing shutoffs after 1.8 seconds when we run it from a Feather, but not if we run it from a Raspberry Pi. Both controllers feed the PCB with 3.3 volts, where its regulated down to ...


I2C devices with unique identifiers.

Started by Roberto Waltman in sci.electronics.design9 years ago 14 replies
I2C

For a project I am working on, I would like to give boards fresh from manufacturing a distinct "identity", before they are assigned a...

For a project I am working on, I would like to give boards fresh from manufacturing a distinct "identity", before they are assigned a serial number, or have a MAC address or IP address programmed, etc. This could be provided by some devices, such as Maxim's DS2411 "Silicon serial number" ( with a "Unique, Factory-Lasered and Tested 64-Bit Registration Number" ) or DS18B20 temperature sens...


flexible ribbon "PCB" to regular PCB

Started by Winfield Hill in sci.electronics.design3 years ago 28 replies

Looking for good ways to connect / solder a flexible ribbon PCB to a regular PCB, without using a connector. We need to be able to pull hard on...

Looking for good ways to connect / solder a flexible ribbon PCB to a regular PCB, without using a connector. We need to be able to pull hard on the link, without the flexible ribbon coming out. Maybe using Molex Premo-Flex, etc., to avoid having to fab the flexible ribbon? We only need four wires, for an I2C connection. -- Thanks, - Win


Multiple Masters on SPI

Started by sms in sci.electronics.design8 years ago 11 replies

I'm working on a design where a Cortex M3 writes data to an SPI Flash memory. The issue is that I have a data acquisition device that also...

I'm working on a design where a Cortex M3 writes data to an SPI Flash memory. The issue is that I have a data acquisition device that also needs to read the SPI Flash. Both devices can only be SPI masters. The UART on the Cortex M3 is being used for something else and I2C is too slow. Essentially we're trying to make the SPI Flash into a dual-port SPI Flash with external logic. In sea...


OLED on PIC18

Started by Jan Panteltje in sci.electronics.design8 years ago

I wrote: > Next will be to display GPS coordinates on the OLED, > then I need to add 24LC1025 logging (same i2c bus), > and port the PIC...

I wrote: > Next will be to display GPS coordinates on the OLED, > then I need to add 24LC1025 logging (same i2c bus), > and port the PIC 16F690 (IIRC) Geiger counter code > and HV controller to this, > and then add the SDcard driver... (SDcard sockets have arrived). Wrote the logging code to 24LC1025 EEPROM, 2.5 days logging of counts per minute, time, and GPS position. Ported the GM count