The BBC has once again delayed its planned launch of the microbit.
The microcomputer was originally scheduled to be given away to 1 million pupils in October last year.
The company says it now plans to start giving teachers their own units after the half-term holidays to help them plan classes.
The school added that it was "pushing for as many services as possible" for students by the end of the term, but could not be more specific about the number and timing.
The idea behind this project has been widely praised, but some teachers worry that they will no longer have enough time to do it fairly this school year.
The Micro Bit is designed to run code written by children that will let them display text and patterns on its 25 LEDs and make use of its built-in sensors.
The idea is that they will be able to create simple games that they can play on their devices.
In addition, they can physically connect it to other hardware or connect it to a smartphone via Bluetooth to perform more complex functions.
The BBC promises to give one to every child in seventh or equivalent.
Last September, it revealed delays caused by power supply problems, adding that teachers will receive equipment by the end of 2015 for children "at the beginning of the New Year" .
But on Wednesday, at the Bette Education Trade Show in London, the BBC said that its schedule was postponed again.
"The main problem is some fine-tuning, " says cerys Griffiths, executive director of BBC learning.
"We created hardware, which is very complex, very precise and very novel.
"what we really want is for teachers to get their equipment before Christmas."
"But our commitment to teachers has always been that we'll get their equipment first, give them time to play, and get to know them."
Some schools have already obtained prototypes of miniature drill bits.
Emily Roland, a teacher at Manchester fairfield Girls High School, said that even the least good students can use them to show smiling faces.
But she added that the delay was cause for concern.
She said: "Some teachers panic at the thought that they can only use them in the six weeks of the summer semester, and they haven't even seen them yet." .
"this summer, it will be very difficult for a considerable number of schools to do this, and some schools will have to postpone until the next school year, and then the question is, who did you give the free gift to?"
Steve Richards, another computing teacher at Eastleigh Community School in London, was more positive about the incident.
"I understand the frustration of other teachers because it's a wonderful thing that's a bit out of reach, " he said.
"But from what we can do (prototype), waiting is worth it."
While the hardware may be delayed, there is already software that allows children to start coding before they receive their microcomputer:
Samsung released the official Android application of micro drill bit at Betta Fish Show
Microsoft launched a web-based tool a few months ago.
There are other resources on the BBC website
To make up for any disappointment, the BBC has also promised to release more copies of the device than originally planned, which means some children from other school years should get one as well.
Ms Griffith also stressed that just because the 7th grade students will receive the micro drill bit later than originally hoped, it doesn't mean that they need more limited time to use these devices.
"It was never intended to be a one-year device, " she said.
"Every child will have their own equipment, so we hope they can use them during the summer vacation.
"We will have a lot of activities and incentives for them to use until the eighth year, so there will not be only one term."