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by julyjim
Sat Jun 16, 2018 2:57 pm
Forum: C/C++
Topic: Writing data to BCM2835 - SPI
Replies: 24
Views: 3450

Re: Writing data to BCM2835 - SPI

I will , reluctantly, reply. ( I need a brake from coding,. otherwise I really do not care any more posting ANYTHING here ). It is obvious, to me, that forum participants are free to criticize my "abrasive style" and I am expected to change to some pleasing BS format. I developed such style after pe...
by julyjim
Sat Jun 16, 2018 2:38 am
Forum: C/C++
Topic: Writing data to BCM2835 - SPI
Replies: 24
Views: 3450

Re: Writing data to BCM2835 - SPI

Saying it different way - if the register is not memory but a hardware why did I went thru memory mapping process? After all the register addresses in datasheet only the lower part of 32 bit address matches the datasheet It is all dynamically mapped to different addresses every time start the app. I...
by julyjim
Fri Jun 15, 2018 9:32 pm
Forum: Beginners
Topic: activating wlan on both RPi 3 and Rpi zero
Replies: 18
Views: 1641

Re: activating wlan on both RPi 3 and Rpi zero

It seem I have been tactfully warned about my "tone".
Before I depart - how am I suppose to sound cheerful if after all this fruitful exchange you tell me that "accessing internet is a piece of cake" ?
The post was NEVER about accessing internet.
Cheers
SOLVED
by julyjim
Fri Jun 15, 2018 9:25 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: More BCM2835 / SPI questions
Replies: 15
Views: 1967

Re: More BCM2835 / SPI questions

Noted
Thanks for all support I have received soi far.
Lets tie a ribbon on it.
by julyjim
Fri Jun 15, 2018 9:20 pm
Forum: C/C++
Topic: Writing data to BCM2835 - SPI
Replies: 24
Views: 3450

Re: Writing data to BCM2835 - SPI

You set TA before you start, then as soon as there is a byte waiting in the FIFO it transmits it.

That is one of the questions I had.
Since I cannot read what I set to SPI_FIFO_DATA - how does it recognize if I write all zeroes as first data?
Seems like catch 22.
by julyjim
Fri Jun 15, 2018 9:05 pm
Forum: C/C++
Topic: Writing data to BCM2835 - SPI
Replies: 24
Views: 3450

Re: Writing data to BCM2835 - SPI

Well , not really same.
I do not particularly like / want a thread ten miles long..
You are the moderator , you decide.
by julyjim
Fri Jun 15, 2018 6:48 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: SPI CLK divisor ?
Replies: 2
Views: 572

SPI CLK divisor ?

There is a note in BCM2835 datasheet / errata about SPI clock. Just for kicks I run this simple code uint32_t divisor = 2; cout << " BCM2835_CORE_CLK_HZ " << dec << +BCM2835_CORE_CLK_HZ << endl; do { cout << " divisor " << divisor << endl; SPI_CLK_reg[0] = BCM2835_CORE_CLK_HZ / divisor; //BCM2835_SP...
by julyjim
Fri Jun 15, 2018 6:24 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: More BCM2835 / SPI questions
Replies: 15
Views: 1967

Re: More BCM2835 / SPI questions

I am not sure to whom I am directing this. I do not object to academic / what if discussion, but it gets of the subject too fast. No, I am not interested in sending ONE bit at a time. I have managed to retrieve data from SPI_FIFO_DATA. Minor detail - since I have way too much scaffolding in my code ...
by julyjim
Fri Jun 15, 2018 3:50 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: More BCM2835 / SPI questions
Replies: 15
Views: 1967

Re: More BCM2835 / SPI questions

I am aware of all of that - after all it is S(erial)PI.
I am just questioning the notion that after physically transmitting one bit the receiver will read what is coming back.
There is no logical reason to do that - responding on single bit transmitted by master and received by slave.
Cheers
by julyjim
Fri Jun 15, 2018 3:44 pm
Forum: C/C++
Topic: Writing data to BCM2835 - SPI
Replies: 24
Views: 3450

Re: Writing data to BCM2835 - SPI

Just had a long walk to ponder on the statement of setting the RDX as an indicator that ONE bit is "received". That is contradictory to SPI protocol of working with minimum of 8 bits. Why would slave responded after receiving 1 bit? I am still not sure what triggers the BCM hardware to actually STAR...
by julyjim
Fri Jun 15, 2018 1:35 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: More BCM2835 / SPI questions
Replies: 15
Views: 1967

Re: More BCM2835 / SPI questions

As Ivar said (Google it ) - keep clam. So what you are saying is that this "bytes" business BCM uses in their datasheet is bogus as I suspected. I will try to modify my SPI_FIFO DATA to "send" only one bit and see what develops. So far my attempt to "read" the data has failed. My code problem for su...
by julyjim
Fri Jun 15, 2018 1:18 pm
Forum: Beginners
Topic: activating wlan on both RPi 3 and Rpi zero
Replies: 18
Views: 1641

Re: activating wlan on both RPi 3 and Rpi zero

My PC is connected via Ethernet (wired) to a "router" and the RPi 3B is also connected Ethernet (wire) to same router. The router goes to "modem" via Ethernet wired connection. The router or modem , I really do not know which, has "wireless" hardware and it is working fine. I suppose the term is VPN...
by julyjim
Fri Jun 15, 2018 1:09 pm
Forum: C/C++
Topic: Writing data to BCM2835 - SPI
Replies: 24
Views: 3450

Re: Writing data to BCM2835 - SPI

Sorry , been there , done that. The code does the job , but gives no feedback, with the exception of monitoring DONE and TXD . But TXD never changes! For one thing - it assumes char to be output - AKA 8 bits. The BCM2537 SPI_FIFO DATA register is 32 bit wide. The "standard " SPI data is 8 bits wide ...
by julyjim
Fri Jun 15, 2018 1:47 am
Forum: Beginners
Topic: activating wlan on both RPi 3 and Rpi zero
Replies: 18
Views: 1641

Re: activating wlan on both RPi 3 and Rpi zero

I think I better RTFM sudo apt-get install hostapd bridge-utils Yes, the "static IP" is now 10.0.1.2 and I thing the TCF is smart enough to "connect" as long as the "Agent" app is running on RPi.. I neglected to say I do have the "luxury model " RPi Zero W so I am shooting for WLAN. Of course there ...
by julyjim
Fri Jun 15, 2018 12:24 am
Forum: Beginners
Topic: activating wlan on both RPi 3 and Rpi zero
Replies: 18
Views: 1641

Re: activating wlan on both RPi 3 and Rpi zero

English is not my mother's tongue - but "it should" is bothersome.
Give me some more time to experiment and get spare SD.
Thanks
by julyjim
Fri Jun 15, 2018 12:18 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: More BCM2835 / SPI questions
Replies: 15
Views: 1967

Re: More BCM2835 / SPI questions

To clarify - I am not using ioctl , just modified BCM2835 C library. Please do not tell me what I can or cannot do "messing around" - this is not Arduino forum! I have managed to set SPI_FIFO DATA and wait for DONE. The "problems" encountered so far - some on this is dupe. Bit 18 TDX never changes -...
by julyjim
Thu Jun 14, 2018 11:35 pm
Forum: Beginners
Topic: activating wlan on both RPi 3 and Rpi zero
Replies: 18
Views: 1641

Re: activating wlan on both RPi 3 and Rpi zero

I really appreciate your reply. however, it does not do much for me. I am not in position to replace my OS - I need to keep my remote software development tools. I may have not emphasized that in my first post. Simply I cannot start from scratch as you suggested. Configuring remote access to RPi was...
by julyjim
Thu Jun 14, 2018 3:29 pm
Forum: Beginners
Topic: activating wlan on both RPi 3 and Rpi zero
Replies: 18
Views: 1641

Re: activating wlan on both RPi 3 and Rpi zero

OK, call me dense. I can connect from PC to RPi via terminal using SSH. No issue here. I am writing C++ code in Eclipse and using TCF to remotely access RPi - no issue here. TCF has "target ID " TCP:10.0.1.2:1534. I started looking into using wlan by doing sudo iwlist wlan0 scan on RPi. Ton of stuff...
by julyjim
Thu Jun 14, 2018 1:55 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: More BCM2835 / SPI questions
Replies: 15
Views: 1967

More BCM2835 / SPI questions

My apology if I have already asked this or posting in wrong forum. All I want is to send SPI data to BCM2835 and verify it got processed in software. I am not interested in verifying actual hardware output, not yet. Here is what I have done so far Configured RPi 3B (raspi-config) for SPI. Verified /...
by julyjim
Thu Jun 14, 2018 1:17 pm
Forum: Beginners
Topic: activating wlan on both RPi 3 and Rpi zero
Replies: 18
Views: 1641

Re: activating wlan on both RPi 3 and Rpi zero

In PI 3 its as easy as clicking the lan icon. Turn on WiFi. Enter key when asked. Ethernet connects automatically when it's plugged in. I switch all the time. It even remembers the WiFi key. If you leave WiFi on with no Wifi avail, you need to reboot or, you will need to renter the key to connect. ...
by julyjim
Thu Jun 14, 2018 1:42 am
Forum: C/C++
Topic: Writing data to BCM2835 - SPI
Replies: 24
Views: 3450

Re: Writing data to BCM2835 - SPI

Please read this as C/C++ question on how to code BCM2835 10.6.1 Polled a) Set CS, CPOL, CPHA as required and set TA = 1. b) Poll TXD writing bytes to SPI_FIFO, RXD reading bytes from SPI_FIFO until all data written. c) Poll DONE until it goes to 1. d) Set TA = 0. I am back, I am still not sure how ...
by julyjim
Tue Jun 12, 2018 8:59 pm
Forum: Beginners
Topic: activating wlan on both RPi 3 and Rpi zero
Replies: 18
Views: 1641

Re: activating wlan on both RPi 3 and Rpi zero

Thanks, I am slowly learning that " Raspberry Pi " is insufficient (description) if one wants to experiment and SOME instructions written earlier obviously cannot make it clear which "model" they are describing. I just did not want to repeat the painful process of activating Ethernet. I suppose if I...
by julyjim
Sun Jun 10, 2018 3:14 pm
Forum: Beginners
Topic: activating wlan on both RPi 3 and Rpi zero
Replies: 18
Views: 1641

activating wlan on both RPi 3 and Rpi zero

I am currently accessing RPi 3 using Ethernet - SSH / TCP . I like to switch to wlan. I have been following this procedure https://www.raspberrypi.org/documentation/configuration/wireless/wireless-cli.md , but to a point. The procedure really does not explain some of the steps. I do not want to wipe...
by julyjim
Sun Jun 10, 2018 1:04 pm
Forum: C/C++
Topic: Writing data to BCM2835 - SPI
Replies: 24
Views: 3450

Re: Writing data to BCM2835 - SPI

Thanks for confirming my suspicion. Since the "DONE" signal never materialize I was just curious what else I can check if I have the SPI set ALL correctly. I guess I'll trace all the SPI set-ups and hopefully find the missing one. I may have bypassed setting the ALT0 functions while coding something...
by julyjim
Sun Jun 10, 2018 12:25 am
Forum: C/C++
Topic: Writing data to BCM2835 - SPI
Replies: 24
Views: 3450

Re: Writing data to BCM2835 - SPI

Sorry, that is not what I asked.
I had to add more feedback to the function so I can monitor the progress.
It still looks as "write to FIFO - DATA " and monitor CS - DONE is about all that is needed to transmit via MOSI .
When I get that done I can "wire loopback" and read "MISO" back.

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