This project is for the firmware programming of a small, plug in, digital timer. Very similar to existing digital timers for turning on and off lamps etc. It has a custom LCD display displaying the current time, backup battery status and the outlet power status (OFF).
It has an internal lithium battery backup for powering the internal clock through a power failure, 2 push buttons for adjusting the current time of day (hours and minutes), another pushbutton for initiating a manual power off cycle and a hidden, recessed CPU reset button.
It has an internal surge protector for the output outlets, 2 relays to separately turn on and off the 115 volt controlled power outlets, and an internally preprogrammed time to activate and deactivate the power.
The timer differs from commercially available lamp timers in that the ON/OFF cycle is pre- programmed to occur at 4AM. At this power cycle time, both power outlets will be de-energized. After one minute, at 4:01AM, the left outlet will re-energize, and one minute later, at 4:02 AM, the right outlet will re-energize. This cycle will perpetuate daily. Note, the outlets re-energize one after the other, one minute apart.
There are 2 LED’s on the front which indicate the power status of each outlet. These are required for UL compliance as the relays are in normally open mode and, when the relays are energized, the outlets will be de-energized. This is so the relays don’t sit energized all day. They are only energized for the 1 minute power cycle time.
The circuit is comprised of 2 PCB’s - a power board and an LCD board (which has the user control buttons and the LCD on it along with the CPU). Output current is small, only an amp or so at 115 V.
In the event of a power failure, the LCD display turns off and the internal backup battery must be able to power the internal clock for up to 6 hours. Upon power resumption, the timer will resume timing of the power cycle. The internal backup battery is charged by an internal charging circuit which must be monitored and controlled by the firmware.
The Manual power cycle button will initiate a power on/off cycle exactly like what occurs at 4AM whenever it is pushed by the user.
The CPU reset button is recessed and accessed with a paper clip. It causes a complete CPU reset and resets the time of day to 12:00 AM.
The circuit and firmware must be UL certified to be compliant with North American consumer safety standards. The firmware requirements for UL certification are attached.
hi
Sir I am an expert electrical engineer I can do it for you I have almost 7 years of experience in this field I assure you quality work and on time delivery
Please have a look at my profile. PLEASE GIVE ME A CHANCE TO PROVE MYSELF.
Regards
Have rich working experience in PIC16F1936 with LCD. Will design the firmware very nicely and will adhere the specification that you have attached. I have more than 18 years of programming experience in C so the firmware design will the best in class. Will use Microchip XC8 compiler for the firmware development . Can start immediately. Will make the firmware ready for testing in 7 days time. Thanks and please let me know. I am sure, I will be able to make you happy by the quality of my work. Best Regards... Roy
i am an electronic engineer with more than 5 years of experience. i can work on this project and make the firmware and hardware required. i can also ship you the prototype. please contact me to discuss details
Hi,
I am very good with micro-controllers and C programming. I have worked on multiple embedded products and delivered state of art code and deliverables.
IM me to discuss the same.
Awaiting your reply.
Regards,
Atif
Dear Sirs
Please see some questions I have.
Question: I can see no reason on rectifying (D2) and filtering (C4, C6, L1, L2, R22, R4) the mains power before the transformer T1. I think T1 should be located before D2.
These are required for UL compliance as the relays are in normally open (CLOSE) mode and, when the relays are energized, the outlets will be de-energized.
Question: normally open or normally close?
Upon power resumption, the timer will resume timing of the power cycle.
Question: What happens when the time of power resumption is between 4:00 and 4:01, 4:01 and 4:02?
The internal backup battery is charged by an internal charging circuit which must be monitored and controlled by the firmware.
Question: How?
The CPU reset button is recessed and accessed with a paper clip. It causes a complete CPU reset and resets the time of day to 12:00 AM.
Question: When adjusting the time, on passing through 4:00AM, 4:01AM and 4:02AM the power cycle shall be performed?
The circuit and firmware must be UL certified to be compliant with North American consumer safety standards. The firmware requirements for UL certification are attached.
Question: Where is the firmware requirements for UL certification?
Best wishes
Antonio Leite
Hello,
I have examined your documents and would like to help you. The task looks good manageable to complete in 5-7 working days. As already explained in the chat, I have worked primary with avr, looking for a good opportunity to switch to microchip products. Primary focused on PIC32 family, but PIC16 should be no problem too. Payment on satisfaction. I am also able to help you on eventual extensions or redesign of schematic and pcb.
Best regards,
Viktor Gotwig,
Cologne, Germany.
Developer of electronic prototypes Hello, I am, I have read very carefully your project and I am very interested I make an aggressive bid to catch it, we are speaking.
Project Execution Steps :
I.)Firmware development for PIC mcu in mplabx ide.
2).Electric Simulation in proteus you verify the results.
3).We go for schematic & pcb layout in Eagle.
4).We send you project deliverables.
The project looks really interesting. If I understand the requirements correctly, the microcontroller will have two outputs for the power outlets and one output for the lithium ion battery charging in addition to the LCD and 4 buttons - hour, min, manual switch and CPU Reset and also have an input to determine if a power failure has occurred or not.
The buttons would need to have necessary functions as described in the documents.
I have extensive experience in C/C++ programming, specially with microcontroller. I also have experience in programming microcontrollers for battery charging if you are in need of that for this project.
For me the steps to complete this project would be -
1. Make sure that all the inputs and outputs are working properly
2. Write the code for hour, min and manual buttons' long press behavior
3. Finish the timing code
Let me know what do you think of my proposal. I am always open to discussion on further details. I would also love to see the final product.
I don't know about this UL certification programming. I know i can program this if you provide me guidelines for certification.
1. ready h/w provided by you.
2. as per my understating i have to write code for the existing hardware.
looking forward.